WO2015057520A1 - Processes of producing fermentation products - Google Patents

Processes of producing fermentation products Download PDF

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Publication number
WO2015057520A1
WO2015057520A1 PCT/US2014/060120 US2014060120W WO2015057520A1 WO 2015057520 A1 WO2015057520 A1 WO 2015057520A1 US 2014060120 W US2014060120 W US 2014060120W WO 2015057520 A1 WO2015057520 A1 WO 2015057520A1
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Prior art keywords
fermentation
mash
starch
containing material
alpha
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PCT/US2014/060120
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French (fr)
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Jason Holmes
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Novozymes A/S
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Publication of WO2015057520A1 publication Critical patent/WO2015057520A1/en

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    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12PFERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P7/00Preparation of oxygen-containing organic compounds
    • C12P7/02Preparation of oxygen-containing organic compounds containing a hydroxy group
    • C12P7/04Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
    • C12P7/06Ethanol, i.e. non-beverage
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12NMICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N1/00Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
    • C12N1/38Chemical stimulation of growth or activity by addition of chemical compounds which are not essential growth factors; Stimulation of growth by removal of a chemical compound
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12PFERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P2203/00Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E50/00Technologies for the production of fuel of non-fossil origin
    • Y02E50/10Biofuels, e.g. bio-diesel

Definitions

  • the present invention relates to processes of producing fermentation products from plant material.
  • the invention also relates to processes of fermenting sugars derived from plant materials using a fermenting organism.
  • the invention also relates to compositions that can be used in processes of the invention and the use thereof.
  • alcohols e.g., ethanol, methanol, butanol, 1 ,3-propanediol
  • organic acids e.g., citric acid, acetic acid, itaconic acid, lactic acid, gluconic acid, gluconate, lactic acid, succinic acid, 2,5-diketo-D-gluconic acid
  • ketones e.g., acetone
  • amino acids e.g., glutamic acid
  • gases e.g., H 2 and C0 2
  • complex compounds including, for example, antibiotics (e.g., penicillin and tetracycline); enzymes; vitamins (e.g., riboflavin, B 12 , beta-carotene); and hormones. Fermentation is also commonly used in the consumable alcohol (e.g., beer and wine), dairy (e.g., in the production of yogurt and cheese),
  • the present invention relates to processes of producing fermentation products from plant materials.
  • the invention provides processes of producing fermentation products, such as especially ethanol, in increased yield, from sugars derived from plant material by fermentation using a fermenting organism.
  • the starting material may be any plant material or a part or constituent thereof.
  • the starting material is starch-containing material.
  • the starting material is lignocellulose-containing material.
  • the sugars, to be fermented into a desired fermentation product may be derived from starch-containing material (i.e. mainly starch) or lignocellulose-containing material (i.e. mainly cellulose or hemicellulose). Fermentation process of the invention
  • the invention relates to processes of fermenting sugars derived from plant material into fermentation products using a fermenting organism, wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
  • chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01 -200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1 -40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
  • chondroitin sulphate is present in an increased concentration in fermentation compared to a similar fermentation wherein no chondroitin sulphate is present and/or has been added.
  • the fermentation product yield such as especially ethanol yield
  • the fermentation product yield is boosted, i.e., increased compared to when no chondroitin sulphate is present or added.
  • Chondroitin sulphate may be added before and/or during fermentation.
  • chondroitin sulphate is added into the fermentation medium, e.g., in form of a composition of the invention further comprising one or more enzymes, preferably glucoamylase, and/or one or more fermenting organisms, preferably yeast.
  • Chondroitin sulphate is according to the invention used as fermentation product yield boosting compound, which means a compound that when present in fermentation, using a fermenting organism, results in increased yield of a desired fermentation product compared to a corresponding fermentation process where no chondroitin sulphate is present or has been added.
  • the invention relates to processes of producing fermentation products, preferably ethanol, from starch-containing material comprising the steps of:
  • the invention relates to processes of producing fermentation products, preferably ethanol, from starch-containing material, preferably granular starch, comprising the steps of:
  • saccharification and fermentation is carried out simultaneously.
  • the invention relates to processes of producing fermentation products, preferably ethanol, from lignocellulose-containing material, comprising the steps of:
  • step (b) hydrolyzing the material obtain in step (a);
  • compositions comprising chondroitin sulphate and further one or more enzymes and/or one or more fermenting organisms.
  • In invention also relates to the use of chondroitin sulphate for propagating fermenting organisms and for use in a fermentation process.
  • Fig. 1 shows the percentage (%) ethanol yield improvement over a Control after 54 hours corn mash fermentation in the presence of 10, 50 and 100 mg chondroitin sulphate/tube (i.e., 5 g mash) and 0.6 AGU/g TS Glucoamylase E.
  • Fig. 2 shows the percentage (%) glycerol produced over a Control after 54 hours corn mash fermentation in the presence of 10, 50 and 100 mg chondroitin sulphate/tube (i.e., 5 g mash) and 0.6 AGU/g TS Glucoamylase E.
  • Fig. 3 shows the percentage (%) residual glucose over a Control after 54 hours corn mash fermentation in the presence of 10, 50 and 100 mg chondroitin sulphate/tube (i.e. 5 g mash) and 0.6 AGU/g TS Glucoamylase E. DETAILED DESCRIPTION OF THE INVENTION
  • the present invention relates to processes of producing fermentation products from plant material, including a fermentation step using a fermenting organism.
  • the present invention provides a means of increasing fermentation product production yield, such as especially ethanol production yield, in fermenting organisms through the alteration of the metabolic pathway. This is done by adding one or more enzymatic cofactors selected from the group of chondroitin sulphate in fermentation.
  • chondroitin sulphate may be of any origin. Chondroitin sulphate (or just “chondroitin”) may be manufactured from natural sources (shark/beef cartilage or bovine trachea) or by synthetic means. Chondroitin sulphate is responsible for many regulatory and structural functions and exists as a proteoglycan when incorporated into living cells. Chondroitin sulphate is believed to be involved in the metabolic pathway of fermenting organisms, such as yeast.
  • Example 1 As described in Example 1 and shown in Fig. 1 the ethanol yield is increased when 10, 50 or 100 mg chondroitin sulphate/tube (5 g mash) is added to 5 g corn mash (35.74% TS (Total Solids)) together with 0.6 AGU/g TS glucoamylase, and fermented for 54 hours, compared to when no chondroitin sulphate is added.
  • the invention relates to processes of fermenting sugars derived from plant material into fermentation products using a fermenting organism, wherein chondroitin sulphate is present and/or added before and/or during fermentation.
  • Chondroitin sulphate may according to the invention be added before and/or during fermentation in an effective amount/concentration.
  • chondroitin sulphate work(s) by altering the metabolic pathway it may, according to the invention, advantageously be present in fermentations by fermenting organisms.
  • chondroitin sulphate concentration is according to the invention higher compared to when no chondroitin sulphate is present or added in fermentation.
  • chondroitin sulphate has a yield boosting effect when producing fermentation products, such as especially ethanol, from starch-containing material in a process including a fermentation step, such as a conventional simultaneous saccharification and fermentation step (SSF step).
  • chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01-200 mg/g mash, preferably 0.02-100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1 -40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
  • the fermenting organism is yeast, filamentous fungus, or a bacterium.
  • the fermenting organism is derived from a strain of Saccharomyces, such as a strain of Saccharomyces cerevisiae.
  • the sugars are derived from starch-containing material.
  • starch-containing materials can be found in the "Starch-Containing Materials"-section below.
  • the starch-containing material is corn.
  • the starch-containing material is a small grain such as wheat.
  • the sugars are derived from lignocellulose-containing material.
  • lignocellulose-containing materials can be found in the "Lignocellulose-Containing Materials (Biomass)"-section below.
  • the lignocellulose-containing material is selected from the group of corn cobs, corn stover, wheat fiber, and bagasse.
  • the fermentation product is an alcohol, preferably ethanol, especially fuel ethanol, potable ethanol and/or industrial ethanol.
  • ethanol especially fuel ethanol, potable ethanol and/or industrial ethanol. Examples of contemplated fermentation products can be found in the "Fermentation Products' -section below.
  • fermenting organism refers to any organism, including bacterial and fungal organisms, including yeast and filamentous fungi, suitable for producing a desired fermentation product.
  • suitable fermenting organisms according to the invention are able to ferment, i.e., convert sugars, such as glucose, fructose, maltose, xylose, mannose and/or arabinose, directly or indirectly into the desired fermentation product.
  • Examples of fermenting organisms include fungal organisms, such as yeast.
  • Preferred yeast includes strains of the genus Saccharomyces, in particular a strain of Saccharomyces cerevisiae or Saccharomyces uvarum; a strain of Pichia, in particular Pichia stipitis or Pichia pastoris; a strain of the genus Candida, in particular a strain of Candida utilis, Candida arabinofermentans, Candida diddensii, Candida sonorensis, Candida shehatae, Candida tropicalis, or Candida boidinii.
  • yeast includes strains of Hansenula, in particular Hansenula polymorpha or Hansenula anomala; strains of Kluyveromyces, in particular Kluyveromyces marxianus or Kluyveromyces fagilis, and strains of Schizosaccharomyces, in particular Schizosaccharomyces pombe.
  • Preferred bacterial fermenting organisms include strains of Escherichia, in particular Escherichia coli, strains of Zymomonas, in particular Zymomonas mobilis, strains of Zymobacter, in particular Zymobactor palmae, strains of Klebsiella in particular Klebsiella oxytoca, strains of Leuconostoc, in particular Leuconostoc mesenteroides, strains of Clostridium, in particular Clostridium butyricum, strains of Enterobacter, in particular Enterobacter aerogenes and strains of Thermoanaerobacter, in particular Thermoanaerobacter BG1 L1 (Appl. Microbiol.
  • Lactobacillus are also envisioned as are strains of Corynebacterium glutamicum R, Bacillus thermoglucosidaisus, and Geobacillus thermoglucosidasius.
  • the fermenting organism is a C6 sugar (hexose) fermenting organism, such as a strain of, e.g., Saccharomyces cerevisiae.
  • C5 sugar (pentose) fermenting organisms are also contemplated. Most C5 sugar fermenting organisms also ferment C6 sugars. Examples of C5 sugar fermenting organisms include strains of Pichia, such as of the species Pichia stipitis. C5 sugar fermenting bacteria are also known. Also some Saccharomyces cerevisae strains ferment C5 (and C6) sugars. Examples are genetically modified strains of Saccharomyces spp that are capable of fermenting C5 sugars include the ones concerned in, e.g., Ho et al., 1998, Applied and Environmental Microbiology, p. 1852-1859 and Karhumaa et al., 2006, Microbial Cell Factories 5:18.
  • the fermenting organism is added in fermentation so that the viable fermenting organism, such as yeast, count per mL of fermentation medium is in the range from 10 5 to 10 12 , preferably from 10 7 to 10 10 , especially about 5x10 7 .
  • yeast includes, e.g., RED STARTM and ETHANOL REDTM yeast (Saccharomyces cerevisiae) (available from Fermentis/Lesaffre, USA), FALI (available from Fleischmann's Yeast, USA), SUPERSTART and THERMOSACCTM fresh yeast (available from Ethanol Technology, Wl, USA), BIOFERM AFT and XR (available from NABC - North American Bioproducts Corporation, GA, USA), GERT STRAND (available from Gert Strand AB, Sweden), and FERMIOL (available from DSM Specialties).
  • RED STARTM and ETHANOL REDTM yeast Sacharomyces cerevisiae
  • FALI available from Fleischmann's Yeast, USA
  • SUPERSTART and THERMOSACCTM fresh yeast available from Ethanol Technology, Wl, USA
  • BIOFERM AFT and XR available from NABC - North American Bioproducts Corporation, GA, USA
  • GERT STRAND available from Gert Strand AB, Sweden
  • the fermenting organism capable of producing a desired fermentation product from fermentable sugars including glucose, fructose maltose, xylose, mannose, and/or arabinose
  • the inoculated fermenting organism pass through a number of stages. Initially growth does not occur. This period is referred to as the "lag phase” and may be considered a period of adaptation.
  • the growth rate gradually increases. After a period of maximum growth the rate ceases and the fermenting organism enters "stationary phase”. After a further period of time the fermenting organism enters the "death phase" where the number of viable cells declines.
  • chondroitin sulphate is added to the fermentation medium when the fermenting organism is in the lag phase.
  • chondroitin sulphate is added to the fermentation medium when the fermenting organism is in exponential phase.
  • chondroitin sulphate is added to the fermentation medium when the fermenting organism is in stationary phase.
  • Fermentation product means a product produced in a process including a fermentation step using a fermenting organism.
  • Fermentation products contemplated according to the invention include alcohols (e.g., ethanol, methanol, butanol); organic acids (e.g., citric acid, acetic acid, itaconic acid, lactic acid, gluconic acid); ketones (e.g., acetone); amino acids (e.g., glutamic acid); gases (e.g., H 2 and C0 2 ); antibiotics (e.g., penicillin and tetracycline); enzymes; vitamins (e.g., riboflavin, B 12 , beta-carotene); and hormones.
  • alcohols e.g., ethanol, methanol, butanol
  • organic acids e.g., citric acid, acetic acid, itaconic acid, lactic acid, gluconic acid
  • ketones e.g., acetone
  • amino acids
  • the fermentation product is ethanol, e.g., fuel ethanol; drinking ethanol, i.e., potable neutral spirits; or industrial ethanol or products used in the consumable alcohol industry (e.g., beer and wine), dairy industry (e.g., fermented dairy products), leather industry and tobacco industry.
  • ethanol e.g., fuel ethanol
  • drinking ethanol i
  • the sugars derived from plant material used in fermentation in a process of the invention may be derived from starch-containing material and/or lignocellulose-containing material.
  • the fermentation conditions are determined based on, e.g., the kind of plant material, the fermentable sugars, the fermenting organism and/or the desired fermentation product.
  • One skilled in the art can easily determine suitable fermentation conditions.
  • the fermentation may according to the invention be carried out at conventionally used conditions. Preferred fermentation processes are anaerobic processes. Fermentation of Sugars Derived from Starch-Containing Materials
  • fermenting organisms may be used for fermenting sugars derived from starch-containing material. Fermentations are often carried out using yeast, such as Saccharomyces cerevisae, as the fermenting organism. However, bacteria and filamentous fungi may also be used as fermenting organisms. Some bacteria have higher fermentation temperature optimum than, e.g., Saccharomyces cerevisae. Therefore, fermentations may in such cases be carried out at temperatures as high as 75°C, e.g., between 40-70°C, such as between 50-60°C. However, bacteria with a significantly lower temperature optimum down to around room temperature (around 20°C) are also known. Examples of suitable fermenting organisms can be found in the "Fermenting Organisms"-section above.
  • the fermentation may in one embodiment go on for 24 to 96 hours, in particular for 36 to 72 hours.
  • the fermentation is carried out at a temperature between 20 to 40°C, preferably 28 to 36°C, in particular around 32°C.
  • the pH is from pH 3 to 6, preferably around pH 4 to 5.
  • SSF simultaneous hydrolysis/saccharification and fermentation
  • the hydrolysing enzyme(s), the fermenting organism(s), and chondroitin sulphate may be added together.
  • the chondroitin sulphate may also be added separately.
  • the temperature is preferably between 20 to 40°C, preferably 28 to 36°C, in particular around 32°C when the fermentation organism is a strain of Saccharomyces cerevisiae and the desired fermentation product is ethanol.
  • the process of the invention may be performed as a batch or as a continuous process.
  • the fermentation process of the invention may be conducted in an ultrafiltration system where the retentate is held under recirculation in the presence of solids, water, and the fermenting organism, and where permeate is the desired fermentation product containing liquid. Equally contemplated if the process is conducted in a continuous membrane reactor with ultrafiltration membranes and where the retentate is held under recirculation in presence of solids, water, the fermenting organism and where the permeate is the fermentation product containing liquid.
  • the fermenting organism may be separated from the fermented slurry and recycled.
  • Fermentations are typically carried out at a pH in the range between 3 and 7, preferably from pH 3.5 to 6, such as around pH 5. Fermentations are typically ongoing for 24-96 hours.
  • fermenting organisms may be used for fermenting sugars derived from lignocellulose-containing materials. Fermentations are typically carried out by yeast, bacteria, or filamentous fungi, including the ones mentioned in the "Fermenting Organisms"-section above. If the aim is C6 fermentable sugars the conditions are usually similar to starch fermentations as described above. However, if the aim is to ferment C5 sugars (e.g., xylose) or a combination of C6 and C5 fermentable sugars the fermenting organism(s) and/or fermentation conditions may differ.
  • C5 sugars e.g., xylose
  • the fermenting organism(s) and/or fermentation conditions may differ.
  • Bacteria fermentations may be carried out at higher temperatures, such as up to 75°C, e.g., between 40-70°C, such as between 50-60°C, than conventional yeast fermentations, which are typically carried out at temperatures from 20-40°C.
  • bacteria fermentations at temperature as low as 20°C are known.
  • Fermentations are typically carried out at a pH in the range between 3 and 7, preferably from pH 3.5 to 6, such as around pH 5. Fermentations are typically ongoing for 24-96 hours.
  • the fermentation product may be separated from the fermented slurry.
  • the slurry may be distilled to extract the desired fermentation product or the desired fermentation product may be extracted from the fermented slurry by micro or membrane filtration techniques. Alternatively the fermentation product may be recovered by stripping. Methods for recovery are well known in the art. Production of Fermentation Products from Starch-Containing Materials
  • the present invention relates to a process for producing a fermentation product, especially ethanol, from starch-containing material, which process includes a liquefaction step and sequentially or simultaneously performed saccharification and fermentation steps.
  • the invention relates to processes for producing fermentation products from starch- containing material comprising the steps of:
  • fermentation is carried out in accordance with the fermentation process of the invention, i.e., wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
  • chondroitin sulphate is added before and/or during the fermentation step in an effective amount/concentration.
  • chondroitin sulphate may be added in a separate saccharification step, such as pre-saccharification step, before fermentation.
  • chondroitin sulphate is added directly to the fermentation medium or the fermenting organism propagation medium.
  • the chondroitin sulphate concentration is according to the invention higher compared to when no such compound(s) is/are added in fermentation.
  • chondroitin sulphate has a yield boosting effect when producing fermentation products, such as especially ethanol, from starch-containing material in a process including a fermentation step, such as a conventional simultaneous saccharification and fermentation step (SSF step).
  • chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01-200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1-40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
  • the fermentation product such as especially ethanol, may optionally be recovered after fermentation, e.g., by distillation.
  • Suitable starch-containing starting materials are listed in the section "Starch-Containing Materials' -section below.
  • Contemplated enzymes are listed in the “Enzymes”-section below.
  • the liquefaction is carried out in the presence of an alpha-amylase, preferably a bacterial alpha-amylase, especially Bacillus alpha-amylase, such as Bacillus stearothermophilus alpha-amylase.
  • the fermenting organism is preferably yeast, preferably a strain of Saccharomyces, especially a strain of Saccharomyces cerevisae.
  • Suitable fermenting organisms are listed in the "Fermenting Organisms"-section above. In a preferred embodiment steps ii) and iii) are carried out sequentially or simultaneously ⁇ i.e., as SSF process).
  • the process of the invention further comprises, prior to liquefaction step i), the steps of:
  • the aqueous slurry may contain from 10-55 wt.-% dry solids, preferably 25-45 wt.-% dry solids, more preferably 30-40 wt.-% dry solids of starch-containing material.
  • the slurry is heated to above the initial gelatinization temperature.
  • Alpha-amylase preferably bacterial alpha-amylase, may be added to the slurry.
  • the slurry is also jet-cooked to further gelatinize the slurry before being subjected to an alpha-amylase in liquefaction step i).
  • liquefaction is carried out as a three-step hot slurry process.
  • the slurry is heated to between 60-95°C, preferably between 80-90°C, and alpha-amylase is added to initiate liquefaction (thinning).
  • the slurry is jet-cooked at a temperature between 95- 140°C, preferably 105-125°C, for 1 -15 minutes, preferably for 3-10 minutes, especially around 5 minutes.
  • the slurry is cooled to 60-95°C, preferably 80-90°C, and more alpha-amylase is added to finalize hydrolysis (secondary liquefaction).
  • the liquefaction process is usually carried out at pH 4.5-6.5, in particular at a pH between 5 and 6. Milled and liquefied starch is known as "mash".
  • the saccharification in step ii) may be carried out using conditions well known in the art. For instance, a full saccharification process may last up to from about 24 to about 72 hours.
  • a pre-saccharification step is done at 40-90 minutes at a temperature between 30-65°C, typically at about 60°C, followed by complete saccharification during fermentation in a simultaneous saccharification and fermentation step (SSF). Saccharification is typically carried out at temperatures from 30-70°C, such as 55-65°C, typically around 60°C, and at a pH between 4 and 5, normally at about pH 4.5.
  • the most widely used process in fermentation product production is simultaneous saccharification and fermentation (SSF) process, in which there is no holding stage for the saccharification.
  • SSF simultaneous saccharification and fermentation
  • the fermenting organism such as yeast, enzymes and chondroitin sulphate may be added together.
  • SSF may typically be carried out at a temperature between 25°C and 40°C, such as between 28°C and 36°C, such as between 30°C and 34°C, such as around 32°C, when the fermentation organism is yeast, such as a strain of Saccharomyces cerevisiae, and the desired fermentation product is ethanol.
  • fermentation products may be fermented at conditions and temperatures, well known to the skilled person in the art, suitable for the fermenting organism in question. According to the invention the temperature may be adjusted up or down during fermentation.
  • a protease is adding during fermentation.
  • proteases can be found in the "Proteases"-section below.
  • the invention relates to processes for producing a fermentation product from starch-containing material without gelatinization of the starch-containing material (i.e., uncooked starch-containing material).
  • the desired fermentation product such as ethanol, can be produced without liquefying the aqueous slurry containing the starch-containing material.
  • a process of the invention includes saccharifying (milled) starch-containing material, especially granular starch, below the initial gelatinization temperature, preferably in the presence of a carbohydrate-source generating enzyme, preferably a glucoamylase, to produce sugars that can be fermented into the desired fermentation product by a suitable fermenting organism.
  • a carbohydrate-source generating enzyme preferably a glucoamylase
  • the desired fermentation product is produced from un-gelatinized (i.e., uncooked) milled starch-containing material, especially granular starch.
  • the invention relates to processes of producing a fermentation product from starch-containing material, comprising the steps of:
  • steps (a) and (b) are carried out simultaneously (i.e., one step fermentation) or sequentially.
  • Chondroitin sulphate is may be added before and/or during the fermentation step, especially during simultaneous saccharification and fermentation in an effective amount/concentration.
  • chondroitin sulphate is added directly to the fermentation medium or the fermenting organism propagation medium.
  • the chondroitin sulphate concentration is according to the invention higher compared to when no chondroitin sulphate is added in fermentation.
  • chondroitin sulphate When added in an effective amount chondroitin sulphate has a yield boosting effect when producing fermentation products, such as especially ethanol, from starch-containing material, especially granular starch, in a process including a fermentation step, such as an one-step process of fermenting ungelatinized starch (i.e., no cook process).
  • chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01 -200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1 -40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
  • the fermentation product such as especially ethanol, may optionally be recovered after fermentation, e.g., by distillation.
  • Suitable starch-containing starting materials are listed in the section "Starch-Containing Materials"-section below.
  • Contemplated enzymes are listed in the “Enzymes”-section below.
  • a glucoamylase and/or an alpha-amylase may be present.
  • Alpha- amylases used are preferably acidic, preferably acid fungal alpha-amylases.
  • the fermenting organism is preferably yeast, preferably a strain of Saccharomyces. Suitable fermenting organisms are listed in the "Fermenting Organisms' -section above.
  • the term "below the initial gelatinization temperature” means below the lowest temperature where gelatinization of the starch commences.
  • Starch heated in water typically begins to gelatinize between 50°C and 75°C; the exact temperature of gelatinization depends on the specific starch, and can readily be determined by the skilled artisan.
  • the initial gelatinization temperature may vary according to the plant species, to the particular variety of the plant species as well as with the growth conditions.
  • the initial gelatinization temperature of a given starch-containing material is the temperature at which birefringence is lost in 5% of the starch granules using the method described by Gorinstein and Lii, 1992, Starc /Starke 44 (12): 461 -466.
  • a slurry of starch-containing material such as granular starch, having 10-55 wt.-% dry solids, preferably 25-45 wt.-% dry solids, more preferably 30-40 wt.-% dry solids of starch-containing material may be prepared.
  • the slurry may include water and/or process waters, such as stillage (backset), scrubber water, evaporator condensate or distillate, side stripper water from distillation, or other fermentation product plant process water. Because the process of the invention is carried out below the initial gelatinization temperature and thus no significant viscosity increase takes place, high levels of stillage may be used if desired.
  • the aqueous slurry contains from about 1 to about 70 vol.-% stillage, preferably 15-60% vol.-% stillage, especially from about 30 to 50 vol.-% stillage.
  • the starch-containing material may be prepared by reducing the particle size, preferably by dry or wet milling, to 0.05 to 3.0 mm, preferably 0.1-0.5 mm. After being subjected to a process of the invention at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91 %, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or preferably at least 99% of the dry solids of the starch-containing material is converted into a soluble starch hydrolyzate.
  • the process of the invention is conducted at a temperature below the initial gelatinization temperature.
  • the temperature at which step (a) is carried out is between 30-75°C, preferably between 45-60°C.
  • step (a) and step (b) are carried out as a simultaneous saccharification and fermentation process.
  • the process is typically carried at a temperature between 25°C and 40°C, such as between 28°C and 36°C, such as between 30°C and 34°C, such as around 32°C.
  • the temperature may be adjusted up or down during fermentation.
  • simultaneous saccharification and fermentation is carried out so that the sugar level, such as glucose level, is kept at a low level such as below 6 wt.-%, preferably below about 3 wt.-%, preferably below about 2 wt.-%, more preferred below about 1 wt.-%., even more preferred below about 0.5%, or even more preferred 0.25% wt.-%, such as below about 0.1 wt.-%.
  • a low levels of sugar can be accomplished by simply employing adjusted quantities of enzyme and fermenting organism.
  • the employed quantities of enzyme and fermenting organism may also be selected to maintain low concentrations of maltose in the fermentation broth. For instance, the maltose level may be kept below about 0.5 wt.-% or below about 0.2 wt.-%.
  • the process of the invention may be carried out at a pH in the range between 3 and 7, preferably from pH 3.5 to 6, or more preferably from pH 4 to 5.
  • a protease is adding during fermentation. Examples of proteases can be found in the "Proteases"-section below.
  • sugars may be derived from starch-containing materials.
  • Any suitable starch-containing starting material including granular starch, may be used according to the present invention.
  • the starting material is generally selected based on the desired fermentation product.
  • starch-containing starting materials suitable for use in a process of present invention, include whole grains, corns, wheat, barley, rye, milo, sago, cassava, tapioca, sorghum, rice, peas, beans, and sweet potatoes, or mixtures thereof, or cereals, or sugar-containing raw materials, such as molasses, fruit materials, sugar cane or sugar beet, potatoes. Contemplated are both waxy and non-waxy types of corn and barley.
  • granular starch means raw uncooked starch, i.e., starch in its natural form found in cereal, tubers or grains. Starch is formed within plant cells as tiny granules insoluble in water. When put in cold water, the starch granules may absorb a small amount of the liquid and swell. At temperatures up to 50°C to 75°C the swelling may be reversible. However, with higher temperatures an irreversible swelling called “gelatinization" begins.
  • Granular starch to be processed may in an embodiment be a highly refined starch, preferably at least 90%, at least 95%, at least 97% or at least 99.5% pure, or it may be a more crude starch containing material comprising milled whole grain including non-starch fractions such as germ residues and fibers.
  • the raw material such as whole grain, is milled in order to open up the structure and allowing for further processing.
  • Two milling processes are preferred according to the invention: wet and dry milling. In dry milling whole kernels are milled and used. Wet milling gives a good separation of germ and meal (starch granules and protein) and is often applied at locations where the starch hydrolyzate is used in production of syrups. Both dry and wet milling is well known in the art of starch processing and is equally contemplated for the process of the invention.
  • the starch-containing material may be reduced in particle size, preferably by dry or wet milling, in order to expose more surface area.
  • the particle size is between 0.05 to 3.0 mm, preferably 0.1-0.5 mm, or so that at least 30%, preferably at least 50%, more preferably at least 70%, even more preferably at least 90% of the starch-containing material fit through a sieve with a 0.05 to 3.0 mm screen, preferably 0.1-0.5 mm screen.
  • the invention relates to processes of producing desired fermentation products from lignocellulose-containing material.
  • Conversion of lignocellulose-containing material into fermentation products, such as ethanol, has the advantages of the ready availability of large amounts of feedstock, including wood, agricultural residues, herbaceous crops, municipal solid wastes etc.
  • Lignocellulose-containing materials primarily consist of cellulose, hemicellulose, and lignin and are often referred to as "biomass”.
  • lignocellulose is not directly accessible to enzymatic hydrolysis. Therefore, the lignocellulose-containing material has to be pre-treated, e.g., by acid hydrolysis under adequate conditions of pressure and temperature, in order to break the lignin seal and disrupt the crystalline structure of cellulose. This causes solubilization of the hemicellulose and cellulose fractions.
  • the cellulose and hemicelluloses can then be hydrolyzed enzymatically, e.g. , by cellulolytic enzymes, to convert the carbohydrate polymers into fermentable sugars which may be fermented into a desired fermentation product, such as ethanol.
  • the fermentation product may be recovered, e.g. , by distillation.
  • the invention relates to a process of producing a fermentation product from lignocellulose-containing material, comprising the steps of:
  • fermentation is carried out in accordance with the fermentation process of the invention, i.e., wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
  • Chondroitin sulphate may be added before and/or during fermentation.
  • chondroitin sulphate is added to the fermentation medium.
  • the fermentation step (c) may be carried in accordance with the fermentation process of the invention. In preferred embodiments the steps are carried out as SSF, HHF, or SHF process steps which will be described further below.
  • the lignocellulose-containing material may according to the invention be pre-treated before being hydrolyzed and fermented.
  • the pre-treated material is hydrolyzed, preferably enzymatically, before and/or during fermentation.
  • the goal of pre- treatment is to separate and/or release cellulose, hemicellulose and/or lignin and this way improve the rate of enzymatic hydrolysis.
  • pre-treatment step (a) may be a conventional pre-treatment step known in the art. Pre-treatment may take place in aqueous slurry.
  • the lignocellulose- containing material may during pre-treatment be present in an amount between 10-80 wt. %, preferably between 20-50 wt. %.
  • the lignocellulose-containing material may according to the invention be chemically, mechanically and/or biologically pre-treated before hydrolysis and/or fermentation.
  • Mechanical treatment (often referred to as physical pre-treatment) may be used alone or in combination with subsequent or simultaneous hydrolysis, especially enzymatic hydrolysis, to promote the separation and/or release of cellulose, hemicellulose and/or lignin.
  • the chemical, mechanical and/or biological pre-treatment is carried out prior to the hydrolysis and/or fermentation.
  • the chemical, mechanical and/or biological pre- treatment is carried out simultaneously with hydrolysis, such as simultaneously with addition of one or more cellulolytic enzymes, or other enzyme activities mentioned below, to release fermentable sugars, such as glucose and/or maltose.
  • the pre-treated lignocellulose-containing material is washed and/or detoxified before or after hydrolysis step (b).
  • This may improve the fermentability of, e.g., dilute-acid hydrolyzed lignocellulose-containing material, such as corn stover.
  • Detoxification may be carried out in any suitable way, e.g., by steam stripping, evaporation, ion exchange, resin or charcoal treatment of the liquid fraction or by washing the pre-treated material.
  • chemical pre-treatment refers to any chemical treatment which promotes the separation and/or release of cellulose, hemicellulose and/or lignin.
  • suitable chemical pre-treatment steps include treatment with; for example, dilute acid, lime, alkaline, organic solvent, ammonia, sulphur dioxide, carbon dioxide.
  • wet oxidation and pH-controlled hydrothermolysis are also contemplated chemical pre-treatments.
  • the chemical pre-treatment is acid treatment, more preferably, a continuous dilute and/or mild acid treatment, such as, treatment with sulfuric acid, or another organic acid, such as acetic acid, citric acid, tartaric acid, succinic acid, or mixtures thereof. Other acids may also be used.
  • Mild acid treatment means in the context of the present invention that the treatment pH lies in the range from 1-5, preferably from pH 1-3. In a specific embodiment the acid concentration is in the range from 0.1 to 2.0 wt. % acid, preferably sulphuric acid.
  • the acid may be mixed or contacted with the material to be fermented according to the invention and the mixture may be held at a temperature in the range of 160-220°C, such as 165-195°C, for periods ranging from minutes to seconds, e.g., 1-60 minutes, such as 2-30 minutes or 3-12 minutes.
  • Addition of strong acids, such as sulphuric acid, may be applied to remove hemicellulose. This enhances the digestibility of cellulose.
  • Cellulose solvent treatment also contemplated according to the invention, has been shown to convert about 90% of cellulose to glucose. It has also been shown that enzymatic hydrolysis could be greatly enhanced when the lignocellulosic structure is disrupted.
  • Alkaline H 2 0 2 , ozone, organosolv (uses Lewis acids, FeCI 3 , (AI) 2 S0 4 in aqueous alcohols), glycerol, dioxane, phenol, or ethylene glycol are among solvents known to disrupt cellulose structure and promote hydrolysis (Mosier et al., 2005, Bioresource Technology 96: 673-686).
  • Alkaline chemical pre-treatment with base e.g., NaOH, Na 2 C0 3 and/or ammonia or the like
  • base e.g., NaOH, Na 2 C0 3 and/or ammonia or the like
  • Pre-treatment methods using ammonia are described in, e.g., WO 2006/1 10891 , WO 2006/1 10899, WO 2006/1 10900, WO 2006/1 10901 , which are hereby incorporated by reference.
  • oxidizing agents such as: sulphite based oxidizing agents or the like.
  • solvent pre-treatments include treatment with DMSO (Dimethyl Sulfoxide) or the like.
  • Chemical pre-treatment is generally carried out for 1 to 60 minutes, such as from 5 to 30 minutes, but may be carried out for shorter or longer periods of time dependent on the material to be pre-treated.
  • mechanical pre-treatment refers to any mechanical or physical pre-treatment which promotes the separation and/or release of cellulose, hemicellulose and/or lignin from lignocellulose-containing material.
  • mechanical pre-treatment includes various types of milling, irradiation, steaming/steam explosion, and hydrothermolysis.
  • Mechanical pre-treatment includes comminution (mechanical reduction of the particle size). Comminution includes dry milling, wet milling and vibratory ball milling. Mechanical pre- treatment may involve high pressure and/or high temperature (steam explosion).
  • high pressure means pressure in the range from 300 to 600 psi, preferably 400 to 500 psi, such as around 450 psi.
  • high temperature means temperatures in the range from about 100 to 300°C, preferably from about 140 to 235°C.
  • mechanical pre-treatment is a batch-process, steam gun hydrolyzer system which uses high pressure and high temperature as defined above. A Sunds Hydrolyzer (available from Sunds Defibrator AB (Sweden) may be used for this.
  • both chemical and mechanical pre-treatments are carried out involving, for example, both dilute or mild acid pretreatment and high temperature and pressure treatment.
  • the chemical and mechanical pretreatment may be carried out sequentially or simultaneously, as desired.
  • the lignocellulose-containing material is subjected to both chemical and mechanical pre-treatment to promote the separation and/or release of cellulose, hemicellulose and/or lignin.
  • pre-treatment is carried out as a dilute or mild acid pretreatment step. In another preferred embodiment pre-treatment is carried out as an ammonia fiber explosion step (or AFEX pre-treatment step).
  • Biological Pre-treatment is carried out as a dilute or mild acid pretreatment step. In another preferred embodiment pre-treatment is carried out as an ammonia fiber explosion step (or AFEX pre-treatment step).
  • biological pre-treatment refers to any biological pre-treatment which promotes the separation and/or release of cellulose, hemicellulose, and/or lignin from the lignocellulose-containing material.
  • Biological pre-treatment techniques can involve applying lignin-solubilizing microorganisms (see, for example, Hsu, T.-A., 1996, Pretreatment of biomass, in Handbook on Bioethanol: Production and Utilization, Wyman, C. E., ed., Taylor & Francis, Washington, DC, 179-212; Ghosh, P., and Singh, A., 1993, Physicochemical and biological treatments for enzymatic/microbial conversion of lignocellulosic biomass, Adv. Appl.
  • the pre-treated lignocellulose-containing material Before and/or during fermentation the pre-treated lignocellulose-containing material may be hydrolyzed in order to break the lignin seal and disrupt the crystalline structure of cellulose. In a preferred embodiment hydrolysis is carried out enzymatically.
  • the pre-treated lignocellulose-containing material to be fermented may be hydrolyzed by one or more hydrolases (class E.C. 3 according to Enzyme Nomenclature), preferably one or more carbohydrases including cellulolytic enzymes and hemicellulolytic enzymes, or combinations thereof.
  • protease, alpha-amylase, glucoamylase and/or the like may also be present during hydrolysis and/or fermentation as the lignocellulose-containing material may include some, e.g., starchy and/or proteinaceous material.
  • the enzyme(s) used for hydrolysis may be capable of directly or indirectly converting carbohydrate polymers into fermentable sugars, such as glucose and/or maltose, which can be fermented into a desired fermentation product, such as ethanol.
  • carbohydrase(s) has(have) cellulolytic and/or hemicellulolytic enzyme activity.
  • hydrolysis is carried out using a cellulolytic enzyme composition further comprising one or more polypeptides having cellulolytic enhancing activity.
  • polypeptide(s) having cellulolytic enhancing activity is of family GH61 origin.
  • suitable and preferred cellulolytic enzyme compositions and polypeptides having cellulolytic enhancing activity are described in the "Cellulases or Cellulolytic Enzyme Polypeptides' -section and “Cellulolytic Enhancing Polypeptides" sections below.
  • Hemicellulose polymers can be broken down by hemicellullolytic enzymes and/or acid hydrolysis to release its five and six carbon sugar components.
  • the six carbon sugars such as glucose, galactose, arabinose, and mannose, can readily be fermented to fermentation products such as ethanol, acetone, butanol, glycerol, citric acid, fumaric acid, etc. by suitable fermenting organisms including yeast.
  • Yeast is the preferred fermenting organism for ethanol fermentation.
  • Preferred are strains of Saccharomyces, especially strains of the species Saccharomyces cerevisiae, preferably strains which are resistant towards high levels of ethanol, i.e., up to, e.g., about 10, 12, 15 or 20 vol. % or more ethanol.
  • Enzymatic hydrolysis is preferably carried out in a suitable aqueous environment under conditions which can readily be determined by one skilled in the art. In a preferred embodiment hydrolysis is carried out at suitable, preferably optimal, conditions for the enzyme(s) in question.
  • Suitable process time, temperature and pH conditions can readily be determined by one skilled in the art.
  • hydrolysis is carried out at a temperature between 25 and 70°C, preferably between 40 and 60°C, especially around 50°C.
  • the step is preferably carried out at a pH in the range from 3-8, preferably pH 4-6.
  • Hydrolysis is typically carried out for between 12 and 96 hours, preferable 16 to 72 hours, more preferably between 24 and 48 hours.
  • Fermentation of lignocellulose derived material is carried out in accordance with a fermentation process of the invention as described above, wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
  • Lignocellulose-containing material may be any material containing lignocellulose.
  • the lignocellulose-containing material contains at least 50 wt. %, preferably at least 70 wt. %, more preferably at least 90 wt. % lignocellulose.
  • the lignocellulose-containing material may also comprise other constituents such as cellulosic material, such as cellulose, hemicellulose and may also comprise constituents such as sugars, such as fermentable sugars and/or un-fermentable sugars.
  • Lignocellulose-containing material is generally found, for example, in the stems, leaves, hulls, husks, and cobs of plants or leaves, branches, and wood of trees.
  • Lignocellulosic material can also be, but is not limited to, herbaceous material, agricultural residues, forestry residues, municipal solid wastes, waste paper, and pulp and paper mill residues. It is understood herein that lignocellulose-containing material may be in the form of plant cell wall material containing lignin, cellulose, and hemi-cellulose in a mixed matrix.
  • the lignocellulose-containing material is corn fiber, rice straw, pine wood, wood chips, poplar, wheat straw, switchgrass, bagasse, paper and pulp processing waste.
  • corn stover corn cobs
  • corn fiber hardwood such as poplar and birch
  • softwood softwood
  • cereal straw such as wheat straw, switch grass, Miscanthus, rice hulls
  • MSW municipal solid waste
  • industrial organic waste office paper, or mixtures thereof.
  • the lignocellulose-containing material is corn stover or corn cobs. In another preferred embodiment, the lignocellulose-containing material is corn fiber. In another preferred embodiment, the lignocellulose-containing material is switch grass. In another preferred embodiment, the lignocellulose-containing material is bagasse.
  • hydrolysis and fermentation is carried out as a simultaneous hydrolysis and fermentation step (SSF).
  • SSF simultaneous hydrolysis and fermentation step
  • hydrolysis step and fermentation step are carried out as hybrid hydrolysis and fermentation (HHF).
  • HHF typically begins with a separate partial hydrolysis step and ends with a simultaneous hydrolysis and fermentation step.
  • the separate partial hydrolysis step is an enzymatic cellulose saccharification step typically carried out at conditions (e.g., at higher temperatures) suitable, preferably optimal, for the hydrolyzing enzyme(s) in question.
  • the subsequent simultaneous hydrolysis and fermentation step is typically carried out at conditions suitable for the fermenting organism(s) (often at lower temperatures than the separate hydrolysis step).
  • hydrolysis and fermentation steps may be carried out as separate hydrolysis and fermentation, where the hydrolysis is taken to completion before initiation of fermentation. This is often referred to as "SHF". Enzymes
  • an alpha-amylase may be used any alpha-amylase.
  • the alpha-amylase is an acid alpha-amylase, e.g., fungal acid alpha- amylase or bacterial acid alpha-amylase.
  • the term "acid alpha-amylase” means an alpha- amylase (E.C. 3.2.1 .1 ) which added in an effective amount has activity optimum at a pH in the range of 3 to 7, preferably from 3.5 to 6, or more preferably from 4-5.
  • bacterial alpha-amylase means any bacterial alpha-amylase classified under EC 3.2.1 .1.
  • a bacterial alpha-amylase used according to the invention may, e.g., be derived from a strain of the genus Bacillus, which is sometimes also referred to as the genus Geobacillus.
  • Bacillus alpha-amylase is derived from a strain of Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus stearothermophilus, Bacillus sp. TS-23, or Bacillus subtilis, but may also be derived from other Bacillus sp.
  • bacterial alpha-amylases include the Bacillus stearothermophilus alpha-amylase of SEQ ID NO: 3 in WO 99/19467, the Bacillus amyloliquefaciens alpha-amylase of SEQ ID NO: 5 in WO 99/19467, and the Bacillus licheniformis alpha-amylase of SEQ ID NO: 4 in WO 99/19467 and the Bacillus sp. TS-23 alpha-amylase disclosed as SEQ ID NO: 1 in WO 2009/061380 (all sequences are hereby incorporated by reference).
  • the bacterial alpha-amylase may be an enzyme having a degree of identity of at least 60%, e.g., at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% to any of the sequences shown in SEQ ID NOS: 3, 4 or 5, respectively, in WO 99/19467 and SEQ ID NO: 1 in WO 2009/061380.
  • the alpha-amylase may be an enzyme having a degree of identity of at least 60%, e.g., at least 70%, at least 80%, at least 90%, at least 91 %, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% to any of the sequences shown in SEQ ID NO: 3 in WO 99/19467.
  • the alpha-amylase is derived from Bacillus stearothermophilus.
  • the Bacillus stearothermophilus alpha-amylase may be a mature wild-type or a mature variant thereof.
  • the mature Bacillus stearothermophilus alpha-amylases may be naturally truncated during recombinant production.
  • the mature Bacillus stearothermophilus alpha-amylase may be a truncated so it has around 491 amino acids (compared to SEQ ID NO: 3 in WO 99/19467), such as from 480-495 amino acids.
  • the Bacillus alpha-amylase may also be a variant and/or hybrid.
  • BSG alpha-amylase Bacillus stearothermophilus alpha-amylase (often referred to as BSG alpha-amylase) variants having a deletion of one or two amino acids at positions R179, G180, 1181 and/or G182, preferably a double deletion disclosed in WO 96/23873 - see, e.g., page 20, lines 1 -10 (hereby incorporated by reference), preferably corresponding to deletion of positions 1181 and G182 compared to the amino acid sequence of Bacillus stearothermophilus alpha-amylase set forth in SEQ ID NO: 3 disclosed in WO 99/19467 or the deletion of amino acids R179 and G180 using SEQ ID NO: 3 in WO 99/19467 (which reference is hereby incorporated by reference).
  • BSG alpha-amylase Bacillus stearothermophilus alpha-amylase
  • Bacillus alpha- amylases especially Bacillus stearothermophilus alpha-amylases, which have a double deletion corresponding to a deletion of positions 181 and 182 and further comprise a N193F substitution (also denoted 1181 * + G182 * + N193F) compared to the wild-type BSG alpha-amylase amino acid sequence set forth in SEQ ID NO: 3 disclosed in WO 99/19467.
  • the bacterial alpha- amylase may also have a substitution in a position corresponding to S239 in the Bacillus licheniformis alpha-amylase shown in SEQ ID NO: 4 in WO 99/19467, or a S242 variant of the Bacillus stearothermophilus alpha-amylase of SEQ ID NO: 3 in WO 99/19467.
  • the variant is a S242A, E or Q variant, preferably a S242Q variant, of the Bacillus stearothermophilus alpha-amylase.
  • the variant is a position E188 variant, preferably E188P variant of the Bacillus stearothermophilus alpha-amylase.
  • Bacillus sp. TS-23 variant disclosed in WO2009/061380 especially variants defined in claim 1 of WO2009/061380.
  • the bacterial alpha-amylase may also be a hybrid bacterial alpha-amylase, e.g., an alpha-amylase comprising 445 C terminal amino acid residues of the Bacillus licheniformis alpha-amylase (shown in SEQ ID NO: 4 of WO 99/19467) and the 37 N terminal amino acid residues of the alpha-amylase derived from Bacillus amyloliquefaciens (shown in SEQ ID NO: 5 of WO 99/19467).
  • this hybrid has one or more, especially all, of the following substitutions:
  • variants having one or more of the following mutations (or corresponding mutations in other Bacillus alpha- amylases): H154Y, A181 T, N190F, A209V and Q264S and/or the deletion of two residues between positions 176 and 179, preferably the deletion of E178 and G179 (using SEQ ID NO: 5 of WO 99/19467 for position numbering).
  • the bacterial alpha-amylase is the mature part of the chimeric alpha- amylase disclosed in Richardson et al., 2002, The Journal of Biological Chemistry 277(29):. 267501 -26507, referred to as BD5088 or a variant thereof.
  • This alpha-amylase is the same as the one shown in SEQ ID NO: 2 in WO 2007134207.
  • the mature enzyme sequence starts after the initial "Met" amino acid in position 1 .
  • the bacterial alpha-amylase is dosed in an amount of 0.0005-5 KNU per g DS (dry solids), preferably 0.001 -1 KNU per g DS, such as around 0.050 KNU per g DS.
  • Fungal alpha-amylases include alpha-amylases derived from a strain of the genus Aspergillus, such as, Aspergillus oryzae, Aspergillus niger and Aspergillis kawachii alpha- amylases.
  • a preferred acidic fungal alpha-amylase is a Fungamyl-like alpha-amylase which is derived from a strain of Aspergillus oryzae.
  • the term "Fungamyl-like alpha-amylase” indicates an alpha-amylase which exhibits a high identity, i.e., more than 70%, more than 75%, more than 80%, more than 85% more than 90%, more than 95%, more than 96%, more than 97%, more than 98%, more than 99% or even 100% identity to the mature part of the amino acid sequence shown in SEQ ID NO: 10 in WO 96/23874.
  • Another preferred acidic alpha-amylase is derived from a strain Aspergillus niger.
  • the acid fungal alpha-amylase is the one from A. niger disclosed as "AMYA_ASPNG" in the Swiss-prot/TeEMBL database under the primary accession no. P56271 and described in WO 89/01969 (Example 3).
  • a commercially available acid fungal alpha- amylase derived from Aspergillus niger is SP288 (available from Novozymes A/S, Denmark).
  • wild-type alpha-amylases include those derived from a strain of the genera Rhizomucor and Meripilus, preferably a strain of Rhizomucor pusillus (WO 2004/055178 incorporated by reference) or Meripilus giganteus.
  • the alpha-amylase is derived from Aspergillus kawachii and disclosed by Kaneko et al., 1996, J. Ferment Bioeng. 81 : 292-298, "Molecular-cloning and determination of the nucleotide-sequence of a gene encoding an acid-stable alpha-amylase from Aspergillus kawachir; and further as EMBL:#AB008370.
  • the fungal alpha-amylase may also be a wild-type enzyme comprising a starch-binding domain (SBD) and an alpha-amylase catalytic domain (i.e., non-hybrid), or a variant thereof.
  • SBD starch-binding domain
  • alpha-amylase catalytic domain i.e., non-hybrid
  • the wild-type alpha-amylase is derived from a strain of Aspergillus kawachii.
  • the fungal acid alpha-amylase is a hybrid alpha-amylase.
  • Preferred examples of fungal hybrid alpha-amylases include the ones disclosed in WO 2005/00331 1 or U.S. application publication no. 2005/0054071 (Novozymes) or U.S. application no. 60/638,614 (Novozymes) which is hereby incorporated by reference.
  • a hybrid alpha- amylase may comprise an alpha-amylase catalytic domain (CD) and a carbohydrate-binding domain/module (CBM), such as a starch binding domain, and optional a linker.
  • CD alpha-amylase catalytic domain
  • CBM carbohydrate-binding domain/module
  • contemplated hybrid alpha-amylases include those disclosed in Table 1 to 5 of the examples in U.S. application no. 60/638,614, including Fungamyl variant with catalytic domain JA1 18 and Athelia rolfsii SBD (SEQ ID NO:100 in US 60/638,614), Rhizomucor pusillus alpha-amylase with Athelia rolfsii AMG linker and SBD (SEQ ID NO:101 in US 60/638,614), Rhizomucor pusillus alpha-amylase with Aspergillus niger glucoamylase linker and SBD (which is disclosed in Table 5 as a combination of amino acid sequences SEQ ID NO: 20, SEQ ID NO: 72 and SEQ ID NO: 96 in U.S.
  • contemplated hybrid alpha-amylases include those disclosed in U.S. application publication no. 2005/0054071 , including those disclosed in Table 3 on page 15, such as Aspergillus niger alpha-amylase with Aspergillus awachii linker and starch binding domain.
  • alpha-amylases which exhibit a high identity to any of above mention alpha-amylases, i.e., more than 70%, more than 75%, more than 80%, more than 85% more than 90%, more than 95%, more than 96%, more than 97%, more than 98%, more than 99% or even 100% identity to the mature enzyme sequences.
  • An acid alpha-amylases may according to the invention be added in an amount of 0.1 to 10 AFAU/g DS, preferably 0.10 to 5 AFAU/g DS, especially 0.3 to 2 AFAU/g DS or 0.001 to 1 FAU-F/g DS, preferably 0.01 to 1 FAU-F/g DS.
  • Preferred commercial compositions comprising alpha-amylase include MYCOLASE from DSM (Gist Brocades), BANTM, TERMAMYLTM SC, FUNGAMYLTM, LIQUOZYMETM X and SANTM SUPER, SANTM EXTRA L (Novozymes MS) and CLARASETM L-40,000, DEX-LOTM, SPEZYMETM FRED, SPEZYMETM AA, SPEZYMETM DELTA AA, SPEZYME XTRATM (Genencor Int., USA), FUELZYMETM (from Verenium Corp, USA) and the acid fungal alpha-amylase sold under the trade name SP288 (available from Novozymes A S, Denmark).
  • carbohydrate-source generating enzyme includes glucoamylase (being glucose generators), beta-amylase and maltogenic amylase (being maltose generators).
  • a carbohydrate-source generating enzyme is capable of producing a carbohydrate that can be used as an energy-source by the fermenting organism(s) in question, for instance, when used in a process of the invention for producing a fermentation product, such as ethanol.
  • the generated carbohydrate may be converted directly or indirectly to the desired fermentation product, preferably ethanol.
  • a mixture of carbohydrate-source generating enzymes may be used.
  • mixtures are mixtures of at least a glucoamylase and an alpha-amylase, especially an acid amylase, even more preferred an acid fungal alpha-amylase.
  • the ratio between acid fungal alpha-amylase activity (AFAU) per glucoamylase activity (AGU) (AFAU per AGU) may in an embodiment of the invention be at least 0.1 , or at least 0.16, such as in the range from 0.12 to 0.50 or more.
  • the ratio between acid fungal alpha-amylase activity (FAU-F) and glucoamylase activity (AGU) ⁇ i.e., FAU-F per AGU) may in an embodiment of the invention be between 0.1 and 100, in particular between 2 and 50, such as in the range from 10-40.
  • a glucoamylase used according to the invention may be derived from any suitable source, e.g., derived from a microorganism or a plant.
  • Preferred glucoamylases are of fungal or bacterial origin, selected from the group consisting of Aspergillus glucoamylases, in particular A. niger G1 or G2 glucoamylase (Boel et al., 1984, EMBO J. 3 (5): 1097-1 102), or variants thereof, such as those disclosed in WO 92/00381 , WO 00/04136 and WO 01/04273 (from Novozymes, Denmark); the A.
  • awamori glucoamylase disclosed in WO 84/02921 , A. oryzae glucoamylase (Agric. Biol. Chem. , 1991 , 55 (4): 941-949), or variants or fragments thereof.
  • Other Aspergillus glucoamylase variants include variants with enhanced thermal stability: G137A and G139A (Chen et al., 1996, Prot. Eng. 9: 499-505); D257E and D293E/Q (Chen et al., 1995, Prot. Eng. 8: 575-582); N182 (Chen et al., 1994, Biochem. J.
  • glucoamylases include Athelia rolfsii (previously denoted Corticium rolfsii) glucoamylase (see U.S. Patent No. 4,727,026 and Nagasaka et al., 1998, "Purification and properties of the raw-starch-degrading glucoamylases from Corticium rolfsii, AppI Microbiol Biotechnol 50:323-330), Talaromyces glucoamylases, in particular derived from Talaromyces emersonii (WO 99/28448), Talaromyces leycettanus (U.S. Patent No. Re. 32,153), Talaromyces duponti, and Talaromyces thermophilus (U.S. Patent No. 4,587,215).
  • Bacterial glucoamylases contemplated include glucoamylases from the genus Clostridium, in particular C. thermoamylolyticum (EP 135,138), and C. thermohydrosulfuricum (WO 86/01831 ).
  • Contemplated fungal glucoamylases include Trametes cingulate (SEQ ID NO: 2), Pachykytospora papyracea; and Leucopaxillus giganteus all disclosed in WO 2006/069289; and Peniophora rufomarginata disclosed in WO2007/124285; or a mixture thereof.
  • hybrid glucoamylase are contemplated according to the invention. Examples include the hybrid glucoamylases disclosed in WO 2005/045018. Specific examples include the hybrid glucoamylase disclosed in Table 1 and 4 of Example 1 (which hybrids are hereby incorporated by reference).
  • the glucoamylase is derived from a strain of the genus Pycnoporus, in particular a strain of Pycnoporus as described in WO 201 1/066576 (SEQ ID NOs 2, 4 or 6), or from a strain of the genus Gloephyllum, in particular a strain of Gloephyllum as described in WO 201 1/068803 (SEQ ID NO: 2, 4, 6, 8, 10, 12, 14 or 16) or a strain of the genus Nigrofomes, in particular a strain of Nigrofomes sp. disclosed in WO 2012/064351 (SEQ ID NO: 2) (all references hereby incorporated by reference).
  • glucoamylases which exhibit a high identity to any of the above-mentioned glucoamylases, i.e., at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, such as 100% identity to any one of the mature parts of the enzyme sequences mentioned above.
  • compositions comprising glucoamylase include AMG 200L; AMG 300 L; SANTM SUPER, SANTM EXTRA L, SPIRIZYMETM PLUS, SPI RIZYMETM FUEL, SPIRIZYMETM B4U, SPIRIZYME ULTRATM and AMGTM E (from Novozymes A/S, Denmark); OPTIDEXTM 300, GC480TM and GC147TM (from Genencor Int., USA); AMIGASETM and AMIGASETM PLUS (from DSM); G-ZYMETM G900, G-ZYMETM and G990 ZR (from Genencor Int.).
  • Glucoamylases may in an embodiment be added in an amount of 0.02-20 AGU/g DS, preferably 0.1 -10 AGU/g DS, especially between 1-5 AGU/g DS, such as 0.1 -2 AGU/g DS, such as 0.5 AGU/g DS or in an amount of 0.0001-20 AGU/g DS, preferably 0.001-10 AGU/g DS, especially between 0.01 -5 AGU/g DS, such as 0.1-2 AGU/g DS.
  • the a beta-amylase (E.C 3.2.1.2) is the name traditionally given to exo-acting maltogenic amylases, which catalyze the hydrolysis of 1 ,4- alpha-glucosidic linkages in amylose, amylopectin and related glucose polymers. Maltose units are successively removed from the non-reducing chain ends in a step-wise manner until the molecule is degraded or, in the case of amylopectin, until a branch point is reached. The maltose released has the beta anomeric configuration, hence the name beta-amylase.
  • Beta-amylases have been isolated from various plants and microorganisms (W.M. Fogarty and C.T. Kelly, 1979, Progress in Industrial Microbiology 15: 1 12-1 15). These beta- amylases are characterized by having optimum temperatures in the range from 40°C to 65°C and optimum pH in the range from 4.5 to 7.
  • a commercially available beta-amylase from barley is NOVOZYMTM WBA from Novozymes A/S, Denmark and SPEZYMETM BBA 1500 from Genencor Int., USA.
  • amylase may also be a maltogenic alpha-amylase.
  • a "maltogenic alpha-amylase" is a "maltogenic alpha-amylase"
  • glucan 1 ,4-alpha-maltohydrolase E.C. 3.2.1.133
  • a maltogenic amylase from Bacillus stearothermophilus strain NCIB 1 1837 is commercially available from Novozymes A/S.
  • Maltogenic alpha-amylases are described in U.S. Patent Nos. 4,598,048, 4,604,355 and 6,162,628, which are hereby incorporated by reference.
  • the maltogenic amylase may in a preferred embodiment be added in an amount of 0.05- 5 mg total protein/gram DS or 0.05- 5 MANU/g DS.
  • a protease used in accordance with the present invention may be any protease, such as of microbial or plant origin.
  • the protease is an acid protease of microbial origin, preferably of fungal or bacterial origin.
  • Suitable proteases include microbial proteases, such as fungal and bacterial proteases.
  • Preferred proteases are acidic proteases, i.e., proteases characterized by the ability to hydrolyze proteins under acidic conditions below pH 7.
  • Contemplated acid fungal proteases include fungal proteases derived from Aspergillus, Mucor, Rhizopus, Candida, Coriolus, Endothia, Enthomophtra, Irpex, Penicillium, Sclerotiumand Torulopsis.
  • proteases derived from Aspergillus niger see, e.g., Koaze et al., 1964, Agr. Biol. Chem. Japan 28: 216), Aspergillus saitoi (see, e.g., Yoshida, 1954, J. Agr. Chem. Soc. Japan 28: 66), Aspergillus awamori (Hayashida et al., 1977, Agric.
  • Contemplated are also neutral or alkaline proteases, such as a protease derived from a strain of Bacillus.
  • a particular protease contemplated for the invention is derived from Bacillus amyloliquefaciens and has the sequence obtainable at Swissprot as Accession No. P06832.
  • proteases having at least 90% identity to amino acid sequence obtainable at Swissprot as Accession No. P06832 such as at least 92%, at least 95%, at least 96%, at least 97%, at least 98%, or particularly at least 99% identity.
  • proteases having at least 90% identity to amino acid sequence disclosed as SEQ.ID.NO: 1 in the WO 2003/048353 such as at 92%, at least 95%, at least 96%, at least 97%, at least 98%, or particularly at least 99% identity.
  • papain-like proteases such as proteases within E.C. 3.4.22. * (cysteine protease), such as EC 3.4.22.2 (papain), EC 3.4.22.6 (chymopapain), EC 3.4.22.7 (asclepain), EC 3.4.22.14 (actinidain), EC 3.4.22.15 (cathepsin L), EC 3.4.22.25 (glycyl endopeptidase) and EC 3.4.22.30 (caricain).
  • cyste protease such as EC 3.4.22.2 (papain), EC 3.4.22.6 (chymopapain), EC 3.4.22.7 (asclepain), EC 3.4.22.14 (actinidain), EC 3.4.22.15 (cathepsin L), EC 3.4.22.25 (glycyl endopeptidase) and EC 3.4.22.30 (caricain).
  • the protease is a protease preparation derived from a strain of Aspergillus, such as Aspergillus oryzae.
  • the protease is derived from a strain of Rhizomucor, preferably Rhizomucor miehei.
  • the protease is a protease preparation, preferably a mixture of a proteolytic preparation derived from a strain of Aspergillus, such as Aspergillus oryzae, and a protease derived from a strain of Rhizomucor, preferably Rhizomucor mehei.
  • Aspartic acid proteases are described in, for example, Handbook of Proteolytic Enzymes, Edited by Barrett, Rawlings and Woessner, Academic Press, San Diego, 1998, Chapter 270). Suitable examples of aspartic acid protease include, e.g., those disclosed in Berka et al., 1990, Gene 96: 313; Berka et al., 1993, Gene 125: 195-198; and Gomi et al., 1993, Biosci. Biotech. Biochem. 57: 1095-1 100, which are hereby incorporated by reference.
  • the protease may be present in an amount of 0.0001 -1 mg enzyme protein per g DS, preferably 0.001 to 0.1 mg enzyme protein per g DS.
  • the protease may be present in an amount of 0.0001 to 1 LAPU/g DS, preferably 0.001 to 0.1 LAPU/g DS and/or 0.0001 to 1 mAU-RH/g DS, preferably 0.001 to 0.1 mAU-RH/g DS or 0.1 -1000 AU/kg DM (dry matter), preferably 1-100 AU/kg DS and most preferably 5-25 AU/kg DS.
  • cellulases or “cellulolytic enzymes” as used herein are understood as comprising the cellobiohydrolases (EC 3.2.1.91 ), e.g., cellobiohydrolase I and cellobiohydrolase II, as well as the endo-glucanases (EC 3.2.1 .4) and beta-glucosidases (EC 3.2.1.21 ). See relevant sections below with further description of such enzymes. In order to be efficient, the digestion of cellulose may require several types of enzymes acting cooperatively.
  • At least three categories of enzymes are often needed to convert cellulose into glucose: endoglucanases (EC 3.2.1 .4) that cut the cellulose chains at random; cellobiohydrolases (EC 3.2.1 .91 ) which cleave cellobiosyl units from the cellulose chain ends and beta-glucosidases (EC 3.2.1.21 ) that convert cellobiose and soluble cellodextrins into glucose.
  • endoglucanases EC 3.2.1 .4
  • cellobiohydrolases EC 3.2.1 .91
  • beta-glucosidases EC 3.2.1.21
  • cellobiohydrolases are the key enzymes for the degradation of native crystalline cellulose.
  • cellobiohydrolase I is defined herein as a cellulose 1 ,4-beta-cellobiosidase (also referred to as Exo-glucanase, Exo-cellobiohydrolase or 1 ,4-beta-cellobiohydrolase) activity, as defined in the enzyme class EC 3.2.1.91 , which catalyzes the hydrolysis of 1 ,4-beta-D-glucosidic linkages in cellulose and cellotetraose, by the release of cellobiose from the non-reducing ends of the chains.
  • the definition of the term “cellobiohydrolase II activity” is identical, except that cellobiohydrolase II attacks from the reducing ends of the chains.
  • the cellulases may comprise a carbohydrate-binding module (CBM) which enhances the binding of the enzyme to a cellulose-containing fiber and increases the efficacy of the catalytic active part of the enzyme.
  • CBM is defined as contiguous amino acid sequence within a carbohydrate-active enzyme with a discreet fold having carbohydrate-binding activity.
  • the cellulases or cellulolytic enzymes may be a cellulolytic preparation as defined in WO 2008/151079 or WO 2013/028928, which are both hereby incorporated by reference.
  • the cellulolytic preparation comprising a polypeptide having cellulolytic enhancing activity (GH61A), preferably the one disclosed in WO 2005/074656.
  • the cellulolytic preparation may further comprise a beta-glucosidase, such as a beta-glucosidase derived from a strain of the genus Trichoderma, Aspergillus, or Penicillium, including the fusion protein having beta-glucosidase activity disclosed in WO 2008/057637 (Novozymes).
  • the cellulolytic preparation may also comprises a CBH II, preferably Thielavia terrestris cellobiohydrolase II (CEL6A).
  • the cellulolytic preparation also comprises a cellulase enzymes preparation, preferably the one derived from Trichoderma reesei.
  • the cellulolytic activity may, in a preferred embodiment, be derived from a fungal source, such as a strain of the genus Trichoderma, preferably a strain of Trichoderma reeser, or a strain of the genus Humicola, such as a strain of Humicola insolens.
  • the cellulolytic enzyme preparation comprises a polypeptide having cellulolytic enhancing activity (GH61A) disclosed in WO 2005/074656; a cellobiohydrolase, such as Thielavia terrestris cellobiohydrolase II (CEL6A), a beta-glucosidase (e.g., the fusion protein disclosed in WO 2008/057637 and cellulolytic enzymes, e.g., derived from Trichoderma reesei.
  • G61A cellulolytic enhancing activity
  • CEL6A Thielavia terrestris cellobiohydrolase II
  • beta-glucosidase e.g., the fusion protein disclosed in WO 2008/057637
  • cellulolytic enzymes e.g., derived from Trichoderma reesei.
  • the cellulolytic enzyme preparation comprises a polypeptide having cellulolytic enhancing activity (GH61A) disclosed in WO 2005/074656; a beta-glucosidase (e.g., the fusion protein disclosed in WO 2008/057637 and cellulolytic enzymes, e.g., derived from Trichoderma reesei.
  • G61A cellulolytic enhancing activity
  • beta-glucosidase e.g., the fusion protein disclosed in WO 2008/057637
  • cellulolytic enzymes e.g., derived from Trichoderma reesei.
  • the cellulolytic enzyme composition is a Trichoderma reesei cellulolytic enzyme composition, further comprising Thermoascus aurantiacus GH61A polypeptide having cellulolytic enhancing activity (SEQ ID NO: 2 in WO 2005/074656) and Aspergillus fumigatus beta-glucosidase (SEQ ID NO: 2 of WO 2005/047499).
  • the cellulolytic enzyme composition is a Trichoderma reesei cellulolytic enzyme composition further comprising Penicillium emersonii GH61A polypeptide disclosed as SEQ ID NO: 2 in WO 201 1/041397, and Aspergillus fumigatus beta-glucosidase disclosed as SEQ ID NO: 2 in WO 2005/047499, or a variant thereof, which variant has one of, preferably all of, the following substitutions: F100D, S283G, N456E, F512Y.
  • the cellulolytic enzyme composition further comprises a cellobiohydrolase I and cellobiohydrolase II derived from Aspergillus fumigatus.
  • the cellulolytic enzyme composition comprises the Aspergillus fumigatus Cel7A CBH I disclosed as SEQ ID NO: 6 in WO201 1/057140 and the Aspergillus fumigatus CBH II disclosed as SEQ ID NO: 18 in WO 201 1/057140.
  • the cellulolytic enzyme composition may also comprise some hemicellulase, such as up to 20% hemicellulase, such as up to 15%, such as up to 10%, such as xylanase and/or xylosidase, such as beta-xylosidase.
  • the cellulolytic enzyme composition comprises Aspergillus fumigatus GH10 xylanase, such as the one disclosed as SEQ ID NO: 6 (Xyl III) in WO 2006/078256, and Aspergillus fumigatus beta-xylosidase, such as the one disclosed in WO 2013/028928 (Example 16 and 17).
  • the cellulolytic enzyme is the commercially available product CELLUCLAST® 1 .5L, CELLUZYMETM, CELLIC CTECTM, CELLIC CTEC2TM, CELLIC CTEC3TM (all available from Novozymes A S, Denmark), ACCELLERASE 1000TM, ACCELLERASE 1500TM, ACCELLERASE DUETTM, ACCELLERASE TRIOTM (all available from DuPont, USA).
  • a cellulase or cellulolytic enzyme may be dosed in the range from 0.1-100 FPU per gram total solids (TS), preferably 0.5-50 FPU per gram TS, especially 1-20 FPU per gram TS.
  • Endoglucanases (EC No. 3.2.1 .4) catalyses endo hydrolysis of 1 ,4-beta-D-glycosidic linkages in cellulose, cellulose derivatives (such as carboxy methyl cellulose and hydroxy ethyl cellulose), lichenin, beta-1 ,4 bonds in mixed beta-1 ,3 glucans such as cereal beta-D-glucans or xyloglucans and other plant material containing cellulosic parts.
  • the authorized name is endo- 1 ,4-beta-D-glucan 4-glucano hydrolase, but the abbreviated term endoglucanase is used in the present specification. Endoglucanase activity may be determined using carboxymethyl cellulose (CMC) hydrolysis according to the procedure of Ghose, 1987, Pure and Appl. Chem. 59: 257-268.
  • Trichoderma preferably a strain of Trichoderma reesei; a strain of the genus Humicola, such as a strain of Humicola insolens; or a strain of Chrysosporium, preferably a strain of Chrysosporium lucknowense.
  • CBH Cellobiohvdrolase
  • cellobiohydrolase means a 1 ,4-beta-D-glucan cellobiohydrolase (E.C. 3.2.1.91 ), which catalyzes the hydrolysis of 1 ,4-beta-D-glucosidic linkages in cellulose, cellooligosaccharides, or any beta-1 ,4-linked glucose containing polymer, releasing cellobiose from the reducing or non-reducing ends of the chain.
  • cellobiohydroloses examples include CBH I and CBH II from
  • the cellulolytic enzyme composition comprises the Aspergillus fumigatus Cel7A CBH I disclosed as SEQ ID NO: 6 in WO201 1/057140 and the Aspergillus fumigatus CBH II disclosed as SEQ ID NO: 18 in WO 201 1/057140.
  • Cellobiohydrolase activity may be determined according to the procedures described by Lever et al., 1972, Anal. Biochem. 47: 273-279 and by van Tilbeurgh et al., 1982, FEBS Letters 149: 152-156; van Tilbeurgh and Claeyssens, 1985, FEBS Letters 187: 283-288.
  • the Lever et al. method is suitable for assessing hydrolysis of cellulose in corn stover and the method of van Tilbeurgh et al. is suitable for determining the cellobiohydrolase activity on a fluorescent disaccharide derivative.
  • beta-glucosidases may be present during hydrolysis.
  • beta-glucosidase means a beta-D-glucoside glucohydrolase (E.C. 3.2.1.21 ), which catalyzes the hydrolysis of terminal non-reducing beta-D-glucose residues with the release of beta-D-glucose.
  • beta-glucosidase activity is determined according to the basic procedure described by Venturi et al., 2002, J. Basic Microbiol. 42: 55-66, except different conditions were employed as described herein.
  • beta-glucosidase activity is defined as 1 .0 ⁇ of p-nitrophenol produced per minute at 50°C, pH 5 from 4 mM p-nitrophenyl-beta-D-glucopyranoside as substrate in 100 mM sodium citrate, 0.01 % TWEEN® 20.
  • the beta-glucosidase is of fungal origin, such as a strain of the genus Trichoderma, Aspergillus or Penicillium.
  • the beta-glucosidase is a derived from Trichoderma reesei, such as the beta-glucosidase encoded by the bgll gene (see Fig. 1 of EP 562,003).
  • the beta-glucosidase is derived from Aspergillus oryzae (recombinantly produced in Aspergillus oryzae according to WO 02/095014).
  • beta-glucosidase is derived from Aspergillus fumigatus such as the one disclosed as SEQ ID NO: 2 in WO 2005/047499, or a variant thereof, which variant has one of, preferably all of, the following substitutions: F100D, S283G, N456E, F512Y.
  • Cellulolytic Enhancing Polypeptides are derived from Aspergillus fumigatus such as the one disclosed as SEQ ID NO: 2 in WO 2005/047499, or a variant thereof, which variant has one of, preferably all of, the following substitutions: F100D, S283G, N456E, F512Y.
  • cellulolytic enhancing activity is defined herein as a biological activity that enhances the hydrolysis of a lignocellulose derived material by proteins having cellulolytic activity.
  • cellulolytic enhancing activity is determined by measuring the increase in reducing sugars or in the increase of the total of cellobiose and glucose from the hydrolysis of a lignocellulose derived material, e.g.
  • pre-treated lignocellulose- containing material by cellulolytic protein under the following conditions: 1 -50 mg of total protein/g of cellulose in PCS (pre-treated corn stover), wherein total protein is comprised of 80- 99.5% w/w cellulolytic protein/g of cellulose in PCS and 0.5-20% w/w protein of cellulolytic enhancing activity for 1 -7 day at 50°C compared to a control hydrolysis with equal total protein loading without cellulolytic enhancing activity (1-50 mg of cellulolytic protein/g of cellulose in PCS).
  • the polypeptides having cellulolytic enhancing activity enhance the hydrolysis of a lignocellulose derived material catalyzed by proteins having cellulolytic activity by reducing the amount of cellulolytic enzyme required to reach the same degree of hydrolysis preferably at least 0.1 -fold, more at least 0.2-fold, more preferably at least 0.3-fold, more preferably at least 0.4-fold, more preferably at least 0.5-fold, more preferably at least 1 -fold, more preferably at least 3-fold, more preferably at least 4-fold, more preferably at least 5-fold, more preferably at least 10-fold, more preferably at least 20-fold, even more preferably at least 30-fold, most preferably at least 50-fold, and even most preferably at least 100-fold.
  • the hydrolysis and/or fermentation is carried out in the presence of a cellulolytic enzyme in combination with a polypeptide having enhancing activity.
  • the polypeptide having enhancing activity is a family GH61A polypeptide.
  • WO 2005/074647 discloses isolated polypeptides having cellulolytic enhancing activity and polynucleotides thereof from Thielavia terrestris.
  • WO 2005/074656 discloses an isolated polypeptide having cellulolytic enhancing activity and a polynucleotide thereof from Thermoascus aurantiacus.
  • U.S. Application Publication No. 2007/0077630 discloses an isolated polypeptide having cellulolytic enhancing activity and a polynucleotide thereof from Trichoderma reesei.
  • the cellulolytic enzyme composition comprising Thermoascus aurantiacus GH61A polypeptide having cellulolytic enhancing activity (SEQ ID NO: 2 in WO 2005/074656).
  • the cellulolytic enzyme composition comprising Penicillium emersonii GH61A polypeptide disclosed as SEQ ID NO: 2 in WO 201 1/041397,
  • Hemicellulose can be broken down by hemicellulases and/or acid hydrolysis to release its five and six carbon sugar components.
  • the lignocellulose derived material may be treated with one or more hemicellulases.
  • hemicellulase suitable for use in hydrolyzing hemicellulose, preferably into xylose may be used.
  • Preferred hemicellulases include xylanases, beta-xylosidase, arabinofuranosidases, acetyl xylan esterase, feruloyl esterase, glucuronidases, galactanase, endo-galactanase, mannases, endo or exo arabinases, exo-galactanses, pectinase, xyloglucanase, or mixtures of two or more thereof.
  • the hemicellulase for use in the present invention is an exo-acting hemicellulase, and more preferably, the hemicellulase is an exo-acting hemicellulase which has the ability to hydrolyze hemicellulose under acidic conditions of below pH 7, preferably pH 3-7.
  • the hemicellulase is a xylanase.
  • the xylanase is of microbial origin, such as of fungal origin (e.g., Trichoderma, Meripilus, Humicola, Aspergillus, Fusarium) or from a bacterium (e.g., Bacillus).
  • the xylanase is derived from a filamentous fungus, preferably derived from a strain of Aspergillus, such as Aspergillus aculeatus or Aspergillus fumigatus; or a strain of Humicola, preferably Humicola lanuginosa.
  • the xylanase may preferably be an endo-1 ,4-beta-xylanase, more preferably an endo-1 ,4-beta- xylanase of GH10 or GH1 1.
  • the xylanase is an Aspergillus aculeatus GH10 xylanase, such as the one disclosed as SEQ ID NO: 2 (Xyl II) in WO W09421785.
  • the xylanase is an Aspergillus fumigatus GH10 xylanase, such as the one disclosed as SEQ ID NO: 6 (Xyl III) in WO 2006/078256.
  • the hemicellulase is a beta-xylosidase.
  • the beta- xylosidase is an Aspergillus fumigatus beta-xylosidase, such as the one disclosed in WO 2013/028928 (Example 16 and 17).
  • Examples of commercial xylanases include SHEARZYMETM and CELLIC HTECTM, CELLIC HTEC2TM CELLIC HTEC3TM from Novozymes A/S, Denmark.
  • Arabinofuranosidase (EC 3.2.1 .55) catalyzes the hydrolysis of terminal non-reducing alpha-L-arabinofuranoside residues in alpha-L-arabinosides.
  • Galactanase (EC 3.2.1.89), arabinogalactan endo-1 ,4-beta-galactosidase, catalyses the endohydrolysis of 1 ,4-D-galactosidic linkages in arabinogalactans.
  • Pectinase (EC 3.2.1 .15) catalyzes the hydrolysis of 1 ,4-alpha-D-galactosiduronic linkages in pectate and other galacturonans.
  • Xyloglucanase catalyzes the hydrolysis of xyloglucan.
  • the hemicellulase may be added in an amount effective to hydrolyze hemicellulose, such as, in amounts from about 0.001 to 0.5 wt.-% of total solids (TS), more preferably from about 0.05 to 0.5 wt.-% of TS.
  • TS total solids
  • Xylanases may be added in amounts of 0.001-1.0 g/kg DM (dry matter) substrate, preferably in the amounts of 0.005-0.5 g/kg DM substrate, and most preferably from 0.05-0.10 g/kg DM substrate.
  • the invention relates to a composition
  • a composition comprising chondroitin sulphate and further one or more enzymes and/or one or more fermenting organisms.
  • composition of the invention may comprise an enzyme from the class of hydrolases (class EC 3 according to Enzyme Nomenclature).
  • the enzyme is selected from the group consisting of cellulase, hemicellulase, protease, alpha-amylase, and glucoamylase, or a mixture thereof.
  • the enzyme is a glucoamylase, such as one listed in the "Glucoamylase' -section above.
  • composition may also comprise a fermenting organism, such as yeast or another fermenting organisms mentioned in the "Fermenting OrganisrrT'-section above.
  • a fermenting organism such as yeast or another fermenting organisms mentioned in the "Fermenting OrganisrrT'-section above.
  • the invention relates to the use of chondroitin sulphate for propagating fermenting organisms, such as yeast.
  • invention also relates to the use of chondroitin sulphate in a fermentation process or a process of the invention.
  • a process of producing a fermentation product from starch-containing material comprising the steps of:
  • alpha-amylase is from the genus Bacillus, such as a strain of Bacillus stearothermophilus, in particular a variant of a Bacillus stearothermophilus alpha-amylase, such as the one shown in SEQ ID NO: 3 in WO 99/019467.
  • step ii) is saccharified using a carbohydrate-source generating enzyme.
  • the carbohydrate-source generating enzyme is a glucoamylase of fungal origin, preferably from a stain of Aspergillus, preferably Aspergillus niger, Aspergillus awamori, or Aspergillus oryzae; or a strain of Trichoderma, preferably T. reesei; or a strain of Talaromyces, preferably T. emersonii, or a strain of Pycnoporus, or a strain of Gloephyllum, or a strain of the Nigrofomes.
  • the carbohydrate-source generating enzyme is a glucoamylase of fungal origin, preferably from a stain of Aspergillus, preferably Aspergillus niger, Aspergillus awamori, or Aspergillus oryzae; or a strain of Trichoderma, preferably T. reesei; or a strain of Talaromyces, preferably T.
  • glucoamylase is derived from a strain of in particular derived from a strain of Talaromyces emersonii disclosed as SEQ ID NO: 34 in WO 99/28448.
  • glucoamylase is derived from a strain of Gloeophyllum, such as a strain of Gloeophyllum sepiarium or Gloeophyllum trabeum, such as one disclosed in WO 201 1/068803 as any of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14 or 16, preferably SEQ ID NO: 2 in WO 201 1/068803 in WO 201 1/068803.
  • a process of producing a fermentation product from lignocellulose-containing material comprising the steps of:
  • step (b) hydrolysis in step (b) and fermentation in step (c) is carried out as a SSF, HHF or SHF process.
  • a composition comprising chondroitin sulphate and one or more enzymes and/or one or more fermenting organisms.
  • composition of paragraph 46, wherein the enzyme(s) is one or more hydrolases (class EC 3 according to Enzyme Nomenclature) selected from the group consisting of cellulases, hemicellulases, proteases, alpha-amylases, glucoamylases, or a mixture thereof.
  • hydrolases class EC 3 according to Enzyme Nomenclature
  • composition of paragraph 46 or 47, wherein the fermenting organism is selected from the group of yeast, filamentous fungus and/or a bacteria.
  • Chondroitin sulphate was sourced from Sigma Product# C9819-5G Glucoamylase E: Blend comprising Talaromyces emersonii glucoamylase disclosed as SEQ ID NO: 34 in W099/28448, Trametes cingulata glucoamylase disclosed as SEQ ID NO: 2 in WO 06/69289, and Rhizomucor pusillus alpha-amylase with Aspergillus niger glucoamylase linker and SBD disclosed as V039 in Table 5 in WO 2006/069290 (ratio about 75:20:5).
  • Yeast Yeast:
  • the degree of identity between two amino acid sequences is determined by the Clustal method (Higgins, 1989, CABIOS 5: 151-153) using the
  • LASERGENETM MEGALIGNTM software (DNASTAR, Inc., Madison, Wl) with an identity table and the following multiple alignment parameters: Gap penalty of 10 and gap length penalty of
  • the Novo Glucoamylase Unit is defined as the amount of enzyme, which hydrolyzes 1 micromole maltose per minute under the standard conditions 37°C, pH 4.3, substrate: maltose 23.2 mM, buffer: acetate 0.1 M, reaction time 5 minutes.
  • An autoanalyzer system may be used. Mutarotase is added to the glucose dehydrogenase reagent so that any alpha-D-glucose present is turned into beta-D-glucose. Glucose dehydrogenase reacts specifically with beta-D-glucose in the reaction mentioned above, forming NADH which is determined using a photometer at 340 nm as a measure of the original glucose concentration.
  • the alpha-amylase activity may be determined using potato starch as substrate. This method is based on the break-down of modified potato starch by the enzyme, and the reaction is followed by mixing samples of the starch/enzyme solution with an iodine solution. Initially, a blackish-blue color is formed, but during the break-down of the starch the blue color gets weaker and gradually turns into a reddish-brown, which is compared to a colored glass standard.
  • KNU Kilo Novo alpha amylase Unit
  • AFAU Acid alpha-amylase activity
  • the activity of an acid alpha-amylase may be measured in FAU-F (Fungal Alpha-Amylase Unit) or AFAU (Acid Fungal Alpha-amylase Units).
  • FAU-F Fungal Alpha-Amylase Units (Fungamyl) is measured relative to an enzyme standard of a declared strength.
  • AFAU Acid alpha-amylase activity
  • Acid alpha-amylase activity may be measured in AFAU (Acid Fungal Alpha-amylase Units), which are determined relative to an enzyme standard. 1 AFAU is defined as the amount of enzyme which degrades 5.260 mg starch dry matter per hour under the below mentioned standard conditions.
  • Acid alpha-amylase, an endo-alpha-amylase (1 ,4-alpha-D-glucan-glucanohydrolase, E.C. 3.2.1.1 ) hydrolyzes alpha-1 ,4-glucosidic bonds in the inner regions of the starch molecule to form dextrins and oligosaccharides with different chain lengths. The intensity of color formed with iodine is directly proportional to the concentration of starch. Amylase activity is determined using reverse colorimetry as a reduction in the concentration of starch under the specified analytical conditions.
  • IODINE 40 pH 2,5 > DEXTRINS + OLIGOSACCHARIDES
  • Substrate Soluble starch, approx. 0.17 g/L Buffer: Citrate, approx. 0.03 M
  • Iodine (I2) 0.03 g/L
  • a rolled filter paper strip (#1 Whatman; 1 X 6 cm; 50 mg) is added to the bottom of a test tube (13 X 100 mm).
  • Enzyme dilutions are designed to produce values slightly above and below the target value of 2.0 mg glucose.
  • the tubes are incubated for 60 mins. at 50°C ( ⁇ 0.1 °C) in a circulating water bath.
  • the tubes are removed from the water bath, and 3.0 mL of DNS reagent is added to each tube to stop the reaction. The tubes are vortexed 3 seconds to mix.
  • a reagent blank is prepared by adding 1.5 mL of citrate buffer to a test tube.
  • a substrate control is prepared by placing a rolled filter paper strip into the bottom of a test tube, and adding 1 .5 mL of citrate buffer.
  • Enzyme controls are prepared for each enzyme dilution by mixing 1 .0 mL of citrate buffer with 0.5 mL of the appropriate enzyme dilution.
  • Glucose standard tubes are prepared by adding 0.5 mL of each dilution to 1.0 mL of citrate buffer.
  • glucose standard tubes are assayed in the same manner as the enzyme assay tubes, and done along with them.
  • each tube is diluted by adding 50 microL from the tube to 200 microL of ddH 2 0 in a 96-well plate. Each well is mixed, and the absorbance is read at 540 nm.
  • a glucose standard curve is prepared by graphing glucose concentration (mg/0.5 mL) for the four standards (G1 -G4) vs. A 540 . This is fitted using a linear regression (Prism Software), and the equation for the line is used to determine the glucose produced for each of the enzyme assay tubes.
  • the proteolytic activity may be determined with denatured hemoglobin as substrate.
  • Anson-Hemoglobin method for the determination of proteolytic activity denatured hemoglobin is digested, and the undigested hemoglobin is precipitated with trichloroacetic acid (TCA).
  • TCA trichloroacetic acid
  • the amount of TCA soluble product is determined with phenol reagent, which gives a blue color with tyrosine and tryptophan.
  • One Anson Unit is defined as the amount of enzyme which under standard conditions (i.e., 25°C, pH 5.5 and 10 min. reaction time) digests hemoglobin at an initial rate such that there is liberated per minute an amount of TCA soluble product which gives the same color with phenol reagent as one milliequivalent of tyrosine.
  • the AU(RH) method is described in EAL-SM-0350 and is available from Novozymes A S
  • the proteolytic activity may be determined with denatured hemoglobin as substrate.
  • Anson-Hemoglobin method for the determination of proteolytic activity denatured hemoglobin is digested, and the undigested hemoglobin is precipitated with trichloroacetic acid (TCA).
  • TCA trichloroacetic acid
  • the amount of TCA soluble product is determined with phenol reagent, which gives a blue color with tyrosine and tryptophan.
  • One Anson Unit is defined as the amount of enzyme which under standard conditions (i.e., 25°C, pH 7.5 and 10 min. reaction time) digests hemoglobin at an initial rate such that there is liberated per minute an amount of TCA soluble product which gives the same color with phenol reagent as one milliequivalent of tyrosine.
  • LAPU Protease assay method
  • LAPU 1 Leucine Amino Peptidase Unit
  • LAPU is described in EB-SM-0298.02/01 available from Novozymes A/S Denmark on request.
  • MANU Medianal Amylase Novo Unit
  • a target of 30 million cells/g mash of hydrated RED STARTM yeast (Saccharomyces cerevisiae) was added to each tube before being incubated in a 32°C water bath for 54 hours. After a 54 hour fermentation time tubes were centrifuged and the liquid fraction was syringe filtered for HPLC analysis of ethanol and glucose.
  • chondroitin sulphate/tube i.e., 5 g mash
  • Fig. 2 shows the glycerol level when adding 10, 50 and 100 mg chondroitin sulphate per tube.
  • Fig. 3 shows the residual glucose levels for 10, 50 and 100 mg chondroitin sulphate per tube (i.e., 5 g mash). Increased levels of glucose in addition to higher ethanol titer indicate a more efficient fermentation is taking place.

Abstract

The invention relates to a process of fermenting sugars derived from plant materials into fermentation products using a fermenting organism, wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation. The invention also relates to processes of producing fermentation products; compositions comprising chondroitin sulphate; and the use of such compounds and blends comprising such compounds.

Description

PROCESSES OF PRODUCING FERMENTATION PRODUCTS
TECHNICAL FIELD
The present invention relates to processes of producing fermentation products from plant material. The invention also relates to processes of fermenting sugars derived from plant materials using a fermenting organism. The invention also relates to compositions that can be used in processes of the invention and the use thereof.
BACKGROUND ART
A vast number of commercial products that are difficult to produce synthetically are today produced by fermenting organisms. Such products including alcohols (e.g., ethanol, methanol, butanol, 1 ,3-propanediol); organic acids (e.g., citric acid, acetic acid, itaconic acid, lactic acid, gluconic acid, gluconate, lactic acid, succinic acid, 2,5-diketo-D-gluconic acid); ketones (e.g., acetone); amino acids (e.g., glutamic acid); gases (e.g., H2 and C02), and more complex compounds, including, for example, antibiotics (e.g., penicillin and tetracycline); enzymes; vitamins (e.g., riboflavin, B12, beta-carotene); and hormones. Fermentation is also commonly used in the consumable alcohol (e.g., beer and wine), dairy (e.g., in the production of yogurt and cheese), leather, and tobacco industries.
A vast number of processes of producing fermentation products, such as ethanol, by fermentation of sugars provided by degradation of starch-containing and/or lignocellulose- containing material are known in the art.
However, production of fermentation products, such as ethanol, from plant materials, is still too costly. Therefore, there is a need for providing processes that can boost the yield of the fermentation product and thereby reducing the production costs.
SUMMARY OF THE INVENTION
The present invention relates to processes of producing fermentation products from plant materials. The invention provides processes of producing fermentation products, such as especially ethanol, in increased yield, from sugars derived from plant material by fermentation using a fermenting organism.
According to the invention the starting material may be any plant material or a part or constituent thereof. In one embodiment the starting material is starch-containing material. In another embodiment the starting material is lignocellulose-containing material. The sugars, to be fermented into a desired fermentation product, may be derived from starch-containing material (i.e. mainly starch) or lignocellulose-containing material (i.e. mainly cellulose or hemicellulose). Fermentation process of the invention
In the first aspect the invention relates to processes of fermenting sugars derived from plant material into fermentation products using a fermenting organism, wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
In an embodiment chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01 -200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1 -40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
Therefore, according to the invention chondroitin sulphate is present in an increased concentration in fermentation compared to a similar fermentation wherein no chondroitin sulphate is present and/or has been added.
When using chondroitin sulphate, in accordance with the invention, the fermentation product yield, such as especially ethanol yield, is boosted, i.e., increased compared to when no chondroitin sulphate is present or added.
Chondroitin sulphate may be added before and/or during fermentation. In an embodiment chondroitin sulphate is added into the fermentation medium, e.g., in form of a composition of the invention further comprising one or more enzymes, preferably glucoamylase, and/or one or more fermenting organisms, preferably yeast.
Chondroitin sulphate is according to the invention used as fermentation product yield boosting compound, which means a compound that when present in fermentation, using a fermenting organism, results in increased yield of a desired fermentation product compared to a corresponding fermentation process where no chondroitin sulphate is present or has been added.
In an aspect, the invention relates to processes of producing fermentation products, preferably ethanol, from starch-containing material comprising the steps of:
i) liquefying starch-containing material using an alpha-amylase;
ii) saccharifying the liquefied material using a carbohydrate-source generating enzyme;
iii) fermenting using a fermenting organism; wherein fermentation is carried out in accordance with a fermentation process of the invention.
In another aspect the invention relates to processes of producing fermentation products, preferably ethanol, from starch-containing material, preferably granular starch, comprising the steps of:
(a) saccharifying starch-containing material at a temperature below the initial gelatinization temperature of said starch-containing material;
(b) fermenting using a fermenting organism;
wherein fermentation is carried out in accordance with a fermentation process of the invention.
In a preferred embodiment saccharification and fermentation is carried out simultaneously.
In a further embodiment the invention relates to processes of producing fermentation products, preferably ethanol, from lignocellulose-containing material, comprising the steps of:
(a) pre-treating lignocellulose-containing material;
(b) hydrolyzing the material obtain in step (a);
(c) fermenting using a fermenting organism;
wherein fermentation is carried out in accordance with a fermentation process of the invention.
In an aspect the invention also relates to compositions comprising chondroitin sulphate and further one or more enzymes and/or one or more fermenting organisms.
In invention also relates to the use of chondroitin sulphate for propagating fermenting organisms and for use in a fermentation process.
BRIEF DESCRIPTION OF THE FIGURES
Fig. 1 shows the percentage (%) ethanol yield improvement over a Control after 54 hours corn mash fermentation in the presence of 10, 50 and 100 mg chondroitin sulphate/tube (i.e., 5 g mash) and 0.6 AGU/g TS Glucoamylase E.
Fig. 2 shows the percentage (%) glycerol produced over a Control after 54 hours corn mash fermentation in the presence of 10, 50 and 100 mg chondroitin sulphate/tube (i.e., 5 g mash) and 0.6 AGU/g TS Glucoamylase E.
Fig. 3 shows the percentage (%) residual glucose over a Control after 54 hours corn mash fermentation in the presence of 10, 50 and 100 mg chondroitin sulphate/tube (i.e. 5 g mash) and 0.6 AGU/g TS Glucoamylase E. DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to processes of producing fermentation products from plant material, including a fermentation step using a fermenting organism. The present invention provides a means of increasing fermentation product production yield, such as especially ethanol production yield, in fermenting organisms through the alteration of the metabolic pathway. This is done by adding one or more enzymatic cofactors selected from the group of chondroitin sulphate in fermentation.
Chondroitin Sulphate
According to the invention chondroitin sulphate may be of any origin. Chondroitin sulphate (or just "chondroitin") may be manufactured from natural sources (shark/beef cartilage or bovine trachea) or by synthetic means. Chondroitin sulphate is responsible for many regulatory and structural functions and exists as a proteoglycan when incorporated into living cells. Chondroitin sulphate is believed to be involved in the metabolic pathway of fermenting organisms, such as yeast.
As described in Example 1 and shown in Fig. 1 the ethanol yield is increased when 10, 50 or 100 mg chondroitin sulphate/tube (5 g mash) is added to 5 g corn mash (35.74% TS (Total Solids)) together with 0.6 AGU/g TS glucoamylase, and fermented for 54 hours, compared to when no chondroitin sulphate is added.
Fermentation Process of the Invention
In the first aspect the invention relates to processes of fermenting sugars derived from plant material into fermentation products using a fermenting organism, wherein chondroitin sulphate is present and/or added before and/or during fermentation.
Chondroitin sulphate may according to the invention be added before and/or during fermentation in an effective amount/concentration. As chondroitin sulphate work(s) by altering the metabolic pathway it may, according to the invention, advantageously be present in fermentations by fermenting organisms.
The chondroitin sulphate concentration is according to the invention higher compared to when no chondroitin sulphate is present or added in fermentation. When added in an effective amount in accordance with the invention chondroitin sulphate has a yield boosting effect when producing fermentation products, such as especially ethanol, from starch-containing material in a process including a fermentation step, such as a conventional simultaneous saccharification and fermentation step (SSF step).
In an embodiment chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01-200 mg/g mash, preferably 0.02-100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1 -40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
In an embodiment the fermenting organism is yeast, filamentous fungus, or a bacterium.
Examples of contemplated fermenting organisms can be found in the "Fermentation Organisms"-section below. In a preferred embodiment the fermenting organism is derived from a strain of Saccharomyces, such as a strain of Saccharomyces cerevisiae.
In an embodiment the sugars are derived from starch-containing material. Examples of starch-containing materials can be found in the "Starch-Containing Materials"-section below. In a preferred embodiment the starch-containing material is corn. In another preferred embodiment the starch-containing material is a small grain such as wheat.
In an embodiment the sugars are derived from lignocellulose-containing material.
Examples of lignocellulose-containing materials can be found in the "Lignocellulose-Containing Materials (Biomass)"-section below. In a preferred embodiment the lignocellulose-containing material is selected from the group of corn cobs, corn stover, wheat fiber, and bagasse.
In a preferred embodiment the fermentation product is an alcohol, preferably ethanol, especially fuel ethanol, potable ethanol and/or industrial ethanol. Examples of contemplated fermentation products can be found in the "Fermentation Products' -section below.
Fermenting Organisms
The term "fermenting organism" refers to any organism, including bacterial and fungal organisms, including yeast and filamentous fungi, suitable for producing a desired fermentation product. Especially suitable fermenting organisms according to the invention are able to ferment, i.e., convert sugars, such as glucose, fructose, maltose, xylose, mannose and/or arabinose, directly or indirectly into the desired fermentation product. Examples of fermenting organisms include fungal organisms, such as yeast. Preferred yeast includes strains of the genus Saccharomyces, in particular a strain of Saccharomyces cerevisiae or Saccharomyces uvarum; a strain of Pichia, in particular Pichia stipitis or Pichia pastoris; a strain of the genus Candida, in particular a strain of Candida utilis, Candida arabinofermentans, Candida diddensii, Candida sonorensis, Candida shehatae, Candida tropicalis, or Candida boidinii. Other contemplated yeast includes strains of Hansenula, in particular Hansenula polymorpha or Hansenula anomala; strains of Kluyveromyces, in particular Kluyveromyces marxianus or Kluyveromyces fagilis, and strains of Schizosaccharomyces, in particular Schizosaccharomyces pombe.
Preferred bacterial fermenting organisms include strains of Escherichia, in particular Escherichia coli, strains of Zymomonas, in particular Zymomonas mobilis, strains of Zymobacter, in particular Zymobactor palmae, strains of Klebsiella in particular Klebsiella oxytoca, strains of Leuconostoc, in particular Leuconostoc mesenteroides, strains of Clostridium, in particular Clostridium butyricum, strains of Enterobacter, in particular Enterobacter aerogenes and strains of Thermoanaerobacter, in particular Thermoanaerobacter BG1 L1 (Appl. Microbiol. Biotech. 77: 61- 86) and Thermoanarobacter ethanolicus, Thermoanaerobacter thermosaccharolyticum, or Thermoanaerobacter mathranii. Strains of Lactobacillus are also envisioned as are strains of Corynebacterium glutamicum R, Bacillus thermoglucosidaisus, and Geobacillus thermoglucosidasius.
In an embodiment the fermenting organism is a C6 sugar (hexose) fermenting organism, such as a strain of, e.g., Saccharomyces cerevisiae.
In connection with especially fermentation of lignocellulose derived materials, C5 sugar (pentose) fermenting organisms are also contemplated. Most C5 sugar fermenting organisms also ferment C6 sugars. Examples of C5 sugar fermenting organisms include strains of Pichia, such as of the species Pichia stipitis. C5 sugar fermenting bacteria are also known. Also some Saccharomyces cerevisae strains ferment C5 (and C6) sugars. Examples are genetically modified strains of Saccharomyces spp that are capable of fermenting C5 sugars include the ones concerned in, e.g., Ho et al., 1998, Applied and Environmental Microbiology, p. 1852-1859 and Karhumaa et al., 2006, Microbial Cell Factories 5:18.
In one embodiment the fermenting organism is added in fermentation so that the viable fermenting organism, such as yeast, count per mL of fermentation medium is in the range from 105 to 1012, preferably from 107 to 1010, especially about 5x107.
Commercially available yeast includes, e.g., RED STAR™ and ETHANOL RED™ yeast (Saccharomyces cerevisiae) (available from Fermentis/Lesaffre, USA), FALI (available from Fleischmann's Yeast, USA), SUPERSTART and THERMOSACC™ fresh yeast (available from Ethanol Technology, Wl, USA), BIOFERM AFT and XR (available from NABC - North American Bioproducts Corporation, GA, USA), GERT STRAND (available from Gert Strand AB, Sweden), and FERMIOL (available from DSM Specialties). According to the invention the fermenting organism capable of producing a desired fermentation product from fermentable sugars, including glucose, fructose maltose, xylose, mannose, and/or arabinose, is preferably grown under precise conditions at a particular growth rate. When the fermenting organism is introduced into/added to the fermentation medium the inoculated fermenting organism pass through a number of stages. Initially growth does not occur. This period is referred to as the "lag phase" and may be considered a period of adaptation. During the next phase referred to as the "exponential phase" the growth rate gradually increases. After a period of maximum growth the rate ceases and the fermenting organism enters "stationary phase". After a further period of time the fermenting organism enters the "death phase" where the number of viable cells declines.
In one embodiment chondroitin sulphate is added to the fermentation medium when the fermenting organism is in the lag phase.
In one embodiment chondroitin sulphate is added to the fermentation medium when the fermenting organism is in exponential phase.
In one embodiment chondroitin sulphate is added to the fermentation medium when the fermenting organism is in stationary phase.
Fermentation Products
The term "fermentation product" means a product produced in a process including a fermentation step using a fermenting organism. Fermentation products contemplated according to the invention include alcohols (e.g., ethanol, methanol, butanol); organic acids (e.g., citric acid, acetic acid, itaconic acid, lactic acid, gluconic acid); ketones (e.g., acetone); amino acids (e.g., glutamic acid); gases (e.g., H2 and C02); antibiotics (e.g., penicillin and tetracycline); enzymes; vitamins (e.g., riboflavin, B12, beta-carotene); and hormones.
In a preferred embodiment the fermentation product is ethanol, e.g., fuel ethanol; drinking ethanol, i.e., potable neutral spirits; or industrial ethanol or products used in the consumable alcohol industry (e.g., beer and wine), dairy industry (e.g., fermented dairy products), leather industry and tobacco industry. Preferred beer types comprise ales, stouts, porters, lagers, bitters, malt liquors, happoushu, high-alcohol beer, low-alcohol beer, low-calorie beer or light beer. Fermentation
The sugars derived from plant material used in fermentation in a process of the invention may be derived from starch-containing material and/or lignocellulose-containing material. The fermentation conditions are determined based on, e.g., the kind of plant material, the fermentable sugars, the fermenting organism and/or the desired fermentation product. One skilled in the art can easily determine suitable fermentation conditions. The fermentation may according to the invention be carried out at conventionally used conditions. Preferred fermentation processes are anaerobic processes. Fermentation of Sugars Derived from Starch-Containing Materials
As mentioned above different kinds of fermenting organisms may be used for fermenting sugars derived from starch-containing material. Fermentations are often carried out using yeast, such as Saccharomyces cerevisae, as the fermenting organism. However, bacteria and filamentous fungi may also be used as fermenting organisms. Some bacteria have higher fermentation temperature optimum than, e.g., Saccharomyces cerevisae. Therefore, fermentations may in such cases be carried out at temperatures as high as 75°C, e.g., between 40-70°C, such as between 50-60°C. However, bacteria with a significantly lower temperature optimum down to around room temperature (around 20°C) are also known. Examples of suitable fermenting organisms can be found in the "Fermenting Organisms"-section above.
For ethanol production using yeast, the fermentation may in one embodiment go on for 24 to 96 hours, in particular for 36 to 72 hours. In an embodiment the fermentation is carried out at a temperature between 20 to 40°C, preferably 28 to 36°C, in particular around 32°C. In an embodiment the pH is from pH 3 to 6, preferably around pH 4 to 5.
Especially contemplated is simultaneous hydrolysis/saccharification and fermentation (referred to as "SSF") where there is no separate holding stage for the hydrolysis/saccharification, meaning that the hydrolysing enzyme(s), the fermenting organism(s), and chondroitin sulphate may be added together. However, it should be understood that the chondroitin sulphate may also be added separately. When fermentation is performed simultaneous with saccharification (i.e., SSF) the temperature is preferably between 20 to 40°C, preferably 28 to 36°C, in particular around 32°C when the fermentation organism is a strain of Saccharomyces cerevisiae and the desired fermentation product is ethanol.
Other fermentation products may be fermented at temperatures known to the skilled person in the art to be suitable for the fermenting organism in question. The process of the invention may be performed as a batch or as a continuous process. The fermentation process of the invention may be conducted in an ultrafiltration system where the retentate is held under recirculation in the presence of solids, water, and the fermenting organism, and where permeate is the desired fermentation product containing liquid. Equally contemplated if the process is conducted in a continuous membrane reactor with ultrafiltration membranes and where the retentate is held under recirculation in presence of solids, water, the fermenting organism and where the permeate is the fermentation product containing liquid.
After fermentation the fermenting organism may be separated from the fermented slurry and recycled.
Fermentations are typically carried out at a pH in the range between 3 and 7, preferably from pH 3.5 to 6, such as around pH 5. Fermentations are typically ongoing for 24-96 hours.
Fermentation of Sugars Derived From Lignocellulose-Containing Materials
As mentioned above different kinds of fermenting organisms may be used for fermenting sugars derived from lignocellulose-containing materials. Fermentations are typically carried out by yeast, bacteria, or filamentous fungi, including the ones mentioned in the "Fermenting Organisms"-section above. If the aim is C6 fermentable sugars the conditions are usually similar to starch fermentations as described above. However, if the aim is to ferment C5 sugars (e.g., xylose) or a combination of C6 and C5 fermentable sugars the fermenting organism(s) and/or fermentation conditions may differ.
Bacteria fermentations may be carried out at higher temperatures, such as up to 75°C, e.g., between 40-70°C, such as between 50-60°C, than conventional yeast fermentations, which are typically carried out at temperatures from 20-40°C. However, bacteria fermentations at temperature as low as 20°C are known. Fermentations are typically carried out at a pH in the range between 3 and 7, preferably from pH 3.5 to 6, such as around pH 5. Fermentations are typically ongoing for 24-96 hours.
Recovery
Subsequent to fermentation the fermentation product may be separated from the fermented slurry. The slurry may be distilled to extract the desired fermentation product or the desired fermentation product may be extracted from the fermented slurry by micro or membrane filtration techniques. Alternatively the fermentation product may be recovered by stripping. Methods for recovery are well known in the art. Production of Fermentation Products from Starch-Containing Materials
Processes for producing fermentation products from gelatinized starch-containing material
In this aspect the present invention relates to a process for producing a fermentation product, especially ethanol, from starch-containing material, which process includes a liquefaction step and sequentially or simultaneously performed saccharification and fermentation steps.
The invention relates to processes for producing fermentation products from starch- containing material comprising the steps of:
i) liquefying starch-containing material using an alpha-amylase;
ii) saccharifying the liquefied material using a carbohydrate-source generating enzyme;
iii) fermenting using a fermenting organism;
wherein fermentation is carried out in accordance with the fermentation process of the invention, i.e., wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
In a preferred embodiment chondroitin sulphate is added before and/or during the fermentation step in an effective amount/concentration. This means that chondroitin sulphate may be added in a separate saccharification step, such as pre-saccharification step, before fermentation. In an embodiment chondroitin sulphate is added directly to the fermentation medium or the fermenting organism propagation medium. The chondroitin sulphate concentration is according to the invention higher compared to when no such compound(s) is/are added in fermentation. When added in an effective amount chondroitin sulphate has a yield boosting effect when producing fermentation products, such as especially ethanol, from starch-containing material in a process including a fermentation step, such as a conventional simultaneous saccharification and fermentation step (SSF step).
In an embodiment chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01-200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1-40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
The fermentation product, such as especially ethanol, may optionally be recovered after fermentation, e.g., by distillation. Suitable starch-containing starting materials are listed in the section "Starch-Containing Materials' -section below. Contemplated enzymes are listed in the "Enzymes"-section below. The liquefaction is carried out in the presence of an alpha-amylase, preferably a bacterial alpha-amylase, especially Bacillus alpha-amylase, such as Bacillus stearothermophilus alpha-amylase. The fermenting organism is preferably yeast, preferably a strain of Saccharomyces, especially a strain of Saccharomyces cerevisae. Suitable fermenting organisms are listed in the "Fermenting Organisms"-section above. In a preferred embodiment steps ii) and iii) are carried out sequentially or simultaneously {i.e., as SSF process).
In a particular embodiment, the process of the invention further comprises, prior to liquefaction step i), the steps of:
x) reducing the particle size of the starch-containing material, preferably by milling; y) forming a slurry comprising the starch-containing material and water.
The aqueous slurry may contain from 10-55 wt.-% dry solids, preferably 25-45 wt.-% dry solids, more preferably 30-40 wt.-% dry solids of starch-containing material. The slurry is heated to above the initial gelatinization temperature. Alpha-amylase, preferably bacterial alpha-amylase, may be added to the slurry. In an embodiment the slurry is also jet-cooked to further gelatinize the slurry before being subjected to an alpha-amylase in liquefaction step i).
In an embodiment liquefaction is carried out as a three-step hot slurry process. The slurry is heated to between 60-95°C, preferably between 80-90°C, and alpha-amylase is added to initiate liquefaction (thinning). Then the slurry is jet-cooked at a temperature between 95- 140°C, preferably 105-125°C, for 1 -15 minutes, preferably for 3-10 minutes, especially around 5 minutes. The slurry is cooled to 60-95°C, preferably 80-90°C, and more alpha-amylase is added to finalize hydrolysis (secondary liquefaction). The liquefaction process is usually carried out at pH 4.5-6.5, in particular at a pH between 5 and 6. Milled and liquefied starch is known as "mash".
The saccharification in step ii) may be carried out using conditions well known in the art. For instance, a full saccharification process may last up to from about 24 to about 72 hours. In an embodiment a pre-saccharification step is done at 40-90 minutes at a temperature between 30-65°C, typically at about 60°C, followed by complete saccharification during fermentation in a simultaneous saccharification and fermentation step (SSF). Saccharification is typically carried out at temperatures from 30-70°C, such as 55-65°C, typically around 60°C, and at a pH between 4 and 5, normally at about pH 4.5.
The most widely used process in fermentation product production, especially ethanol production, is simultaneous saccharification and fermentation (SSF) process, in which there is no holding stage for the saccharification. This means that the fermenting organism, such as yeast, enzymes and chondroitin sulphate may be added together.
SSF may typically be carried out at a temperature between 25°C and 40°C, such as between 28°C and 36°C, such as between 30°C and 34°C, such as around 32°C, when the fermentation organism is yeast, such as a strain of Saccharomyces cerevisiae, and the desired fermentation product is ethanol.
Other fermentation products may be fermented at conditions and temperatures, well known to the skilled person in the art, suitable for the fermenting organism in question. According to the invention the temperature may be adjusted up or down during fermentation.
In an embodiment a protease is adding during fermentation. Examples of proteases can be found in the "Proteases"-section below.
Processes for Producing Fermentation Products from Un-gelatinized Starch-containing Material In this aspect the invention relates to processes for producing a fermentation product from starch-containing material without gelatinization of the starch-containing material (i.e., uncooked starch-containing material). According to the invention the desired fermentation product, such as ethanol, can be produced without liquefying the aqueous slurry containing the starch-containing material. In one embodiment a process of the invention includes saccharifying (milled) starch-containing material, especially granular starch, below the initial gelatinization temperature, preferably in the presence of a carbohydrate-source generating enzyme, preferably a glucoamylase, to produce sugars that can be fermented into the desired fermentation product by a suitable fermenting organism.
In this embodiment the desired fermentation product, especially ethanol, is produced from un-gelatinized (i.e., uncooked) milled starch-containing material, especially granular starch.
Accordingly, in this aspect the invention relates to processes of producing a fermentation product from starch-containing material, comprising the steps of:
(a) saccharifying starch-containing material at a temperature below the initial gelatinization temperature of said starch-containing material,
(b) fermenting using a fermenting organism,
wherein fermentation is carried out in accordance with the fermentation process of the invention, i.e., wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation. In a preferred embodiment steps (a) and (b) are carried out simultaneously (i.e., one step fermentation) or sequentially. Chondroitin sulphate is may be added before and/or during the fermentation step, especially during simultaneous saccharification and fermentation in an effective amount/concentration. In an embodiment chondroitin sulphate is added directly to the fermentation medium or the fermenting organism propagation medium. The chondroitin sulphate concentration is according to the invention higher compared to when no chondroitin sulphate is added in fermentation. When added in an effective amount chondroitin sulphate has a yield boosting effect when producing fermentation products, such as especially ethanol, from starch-containing material, especially granular starch, in a process including a fermentation step, such as an one-step process of fermenting ungelatinized starch (i.e., no cook process).
In an embodiment chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01 -200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1 -40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1-25 mg/g mash, such as around 10 mg/g mash.
The fermentation product, such as especially ethanol, may optionally be recovered after fermentation, e.g., by distillation. Suitable starch-containing starting materials are listed in the section "Starch-Containing Materials"-section below. Contemplated enzymes are listed in the "Enzymes"-section below. A glucoamylase and/or an alpha-amylase may be present. Alpha- amylases used are preferably acidic, preferably acid fungal alpha-amylases. The fermenting organism is preferably yeast, preferably a strain of Saccharomyces. Suitable fermenting organisms are listed in the "Fermenting Organisms' -section above.
The term "below the initial gelatinization temperature" means below the lowest temperature where gelatinization of the starch commences. Starch heated in water typically begins to gelatinize between 50°C and 75°C; the exact temperature of gelatinization depends on the specific starch, and can readily be determined by the skilled artisan. Thus, the initial gelatinization temperature may vary according to the plant species, to the particular variety of the plant species as well as with the growth conditions. In the context of this invention the initial gelatinization temperature of a given starch-containing material is the temperature at which birefringence is lost in 5% of the starch granules using the method described by Gorinstein and Lii, 1992, Starc /Starke 44 (12): 461 -466.
Before step (a) a slurry of starch-containing material, such as granular starch, having 10-55 wt.-% dry solids, preferably 25-45 wt.-% dry solids, more preferably 30-40 wt.-% dry solids of starch-containing material may be prepared. The slurry may include water and/or process waters, such as stillage (backset), scrubber water, evaporator condensate or distillate, side stripper water from distillation, or other fermentation product plant process water. Because the process of the invention is carried out below the initial gelatinization temperature and thus no significant viscosity increase takes place, high levels of stillage may be used if desired. In an embodiment the aqueous slurry contains from about 1 to about 70 vol.-% stillage, preferably 15-60% vol.-% stillage, especially from about 30 to 50 vol.-% stillage.
The starch-containing material may be prepared by reducing the particle size, preferably by dry or wet milling, to 0.05 to 3.0 mm, preferably 0.1-0.5 mm. After being subjected to a process of the invention at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91 %, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or preferably at least 99% of the dry solids of the starch-containing material is converted into a soluble starch hydrolyzate.
The process of the invention is conducted at a temperature below the initial gelatinization temperature. Preferably the temperature at which step (a) is carried out is between 30-75°C, preferably between 45-60°C.
In a preferred embodiment step (a) and step (b) are carried out as a simultaneous saccharification and fermentation process. In such preferred embodiment the process is typically carried at a temperature between 25°C and 40°C, such as between 28°C and 36°C, such as between 30°C and 34°C, such as around 32°C. According to the invention the temperature may be adjusted up or down during fermentation.
In an embodiment simultaneous saccharification and fermentation is carried out so that the sugar level, such as glucose level, is kept at a low level such as below 6 wt.-%, preferably below about 3 wt.-%, preferably below about 2 wt.-%, more preferred below about 1 wt.-%., even more preferred below about 0.5%, or even more preferred 0.25% wt.-%, such as below about 0.1 wt.-%. Such low levels of sugar can be accomplished by simply employing adjusted quantities of enzyme and fermenting organism. A skilled person in the art can easily determine which quantities of enzyme and fermenting organism to use. The employed quantities of enzyme and fermenting organism may also be selected to maintain low concentrations of maltose in the fermentation broth. For instance, the maltose level may be kept below about 0.5 wt.-% or below about 0.2 wt.-%.
The process of the invention may be carried out at a pH in the range between 3 and 7, preferably from pH 3.5 to 6, or more preferably from pH 4 to 5. In an embodiment a protease is adding during fermentation. Examples of proteases can be found in the "Proteases"-section below.
Starch-Containing Materials
According to the invention sugars may be derived from starch-containing materials. Any suitable starch-containing starting material, including granular starch, may be used according to the present invention. The starting material is generally selected based on the desired fermentation product. Examples of starch-containing starting materials, suitable for use in a process of present invention, include whole grains, corns, wheat, barley, rye, milo, sago, cassava, tapioca, sorghum, rice, peas, beans, and sweet potatoes, or mixtures thereof, or cereals, or sugar-containing raw materials, such as molasses, fruit materials, sugar cane or sugar beet, potatoes. Contemplated are both waxy and non-waxy types of corn and barley.
The term "granular starch" means raw uncooked starch, i.e., starch in its natural form found in cereal, tubers or grains. Starch is formed within plant cells as tiny granules insoluble in water. When put in cold water, the starch granules may absorb a small amount of the liquid and swell. At temperatures up to 50°C to 75°C the swelling may be reversible. However, with higher temperatures an irreversible swelling called "gelatinization" begins. Granular starch to be processed may in an embodiment be a highly refined starch, preferably at least 90%, at least 95%, at least 97% or at least 99.5% pure, or it may be a more crude starch containing material comprising milled whole grain including non-starch fractions such as germ residues and fibers. The raw material, such as whole grain, is milled in order to open up the structure and allowing for further processing. Two milling processes are preferred according to the invention: wet and dry milling. In dry milling whole kernels are milled and used. Wet milling gives a good separation of germ and meal (starch granules and protein) and is often applied at locations where the starch hydrolyzate is used in production of syrups. Both dry and wet milling is well known in the art of starch processing and is equally contemplated for the process of the invention.
The starch-containing material may be reduced in particle size, preferably by dry or wet milling, in order to expose more surface area. In an embodiment the particle size is between 0.05 to 3.0 mm, preferably 0.1-0.5 mm, or so that at least 30%, preferably at least 50%, more preferably at least 70%, even more preferably at least 90% of the starch-containing material fit through a sieve with a 0.05 to 3.0 mm screen, preferably 0.1-0.5 mm screen. Production of Fermentation Products from Liqnocellulose-Containinq Material (Biomass)
In this aspect the invention relates to processes of producing desired fermentation products from lignocellulose-containing material. Conversion of lignocellulose-containing material into fermentation products, such as ethanol, has the advantages of the ready availability of large amounts of feedstock, including wood, agricultural residues, herbaceous crops, municipal solid wastes etc. Lignocellulose-containing materials primarily consist of cellulose, hemicellulose, and lignin and are often referred to as "biomass".
The structure of lignocellulose is not directly accessible to enzymatic hydrolysis. Therefore, the lignocellulose-containing material has to be pre-treated, e.g., by acid hydrolysis under adequate conditions of pressure and temperature, in order to break the lignin seal and disrupt the crystalline structure of cellulose. This causes solubilization of the hemicellulose and cellulose fractions. The cellulose and hemicelluloses can then be hydrolyzed enzymatically, e.g. , by cellulolytic enzymes, to convert the carbohydrate polymers into fermentable sugars which may be fermented into a desired fermentation product, such as ethanol. Optionally the fermentation product may be recovered, e.g. , by distillation.
In this aspect the invention relates to a process of producing a fermentation product from lignocellulose-containing material, comprising the steps of:
(a) pre-treating lignocellulose-containing material;
(b) hydrolyzing the material;
(c) fermenting using a fermenting organism;
wherein fermentation is carried out in accordance with the fermentation process of the invention, i.e., wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
Chondroitin sulphate may be added before and/or during fermentation. In a preferred embodiment chondroitin sulphate is added to the fermentation medium. The fermentation step (c) may be carried in accordance with the fermentation process of the invention. In preferred embodiments the steps are carried out as SSF, HHF, or SHF process steps which will be described further below. Pre-treatment
The lignocellulose-containing material may according to the invention be pre-treated before being hydrolyzed and fermented. In a preferred embodiment the pre-treated material is hydrolyzed, preferably enzymatically, before and/or during fermentation. The goal of pre- treatment is to separate and/or release cellulose, hemicellulose and/or lignin and this way improve the rate of enzymatic hydrolysis.
According to the invention pre-treatment step (a) may be a conventional pre-treatment step known in the art. Pre-treatment may take place in aqueous slurry. The lignocellulose- containing material may during pre-treatment be present in an amount between 10-80 wt. %, preferably between 20-50 wt. %.
Chemical, Mechanical and/or Biological Pre-treatment
The lignocellulose-containing material may according to the invention be chemically, mechanically and/or biologically pre-treated before hydrolysis and/or fermentation. Mechanical treatment (often referred to as physical pre-treatment) may be used alone or in combination with subsequent or simultaneous hydrolysis, especially enzymatic hydrolysis, to promote the separation and/or release of cellulose, hemicellulose and/or lignin.
Preferably, the chemical, mechanical and/or biological pre-treatment is carried out prior to the hydrolysis and/or fermentation. Alternatively, the chemical, mechanical and/or biological pre- treatment is carried out simultaneously with hydrolysis, such as simultaneously with addition of one or more cellulolytic enzymes, or other enzyme activities mentioned below, to release fermentable sugars, such as glucose and/or maltose.
In an embodiment of the invention the pre-treated lignocellulose-containing material is washed and/or detoxified before or after hydrolysis step (b). This may improve the fermentability of, e.g., dilute-acid hydrolyzed lignocellulose-containing material, such as corn stover. Detoxification may be carried out in any suitable way, e.g., by steam stripping, evaporation, ion exchange, resin or charcoal treatment of the liquid fraction or by washing the pre-treated material. Chemical Pre-treatment
According to the present invention "chemical pre-treatment" refers to any chemical treatment which promotes the separation and/or release of cellulose, hemicellulose and/or lignin. Examples of suitable chemical pre-treatment steps include treatment with; for example, dilute acid, lime, alkaline, organic solvent, ammonia, sulphur dioxide, carbon dioxide. Further, wet oxidation and pH-controlled hydrothermolysis are also contemplated chemical pre-treatments.
Preferably, the chemical pre-treatment is acid treatment, more preferably, a continuous dilute and/or mild acid treatment, such as, treatment with sulfuric acid, or another organic acid, such as acetic acid, citric acid, tartaric acid, succinic acid, or mixtures thereof. Other acids may also be used. Mild acid treatment means in the context of the present invention that the treatment pH lies in the range from 1-5, preferably from pH 1-3. In a specific embodiment the acid concentration is in the range from 0.1 to 2.0 wt. % acid, preferably sulphuric acid. The acid may be mixed or contacted with the material to be fermented according to the invention and the mixture may be held at a temperature in the range of 160-220°C, such as 165-195°C, for periods ranging from minutes to seconds, e.g., 1-60 minutes, such as 2-30 minutes or 3-12 minutes. Addition of strong acids, such as sulphuric acid, may be applied to remove hemicellulose. This enhances the digestibility of cellulose.
Cellulose solvent treatment, also contemplated according to the invention, has been shown to convert about 90% of cellulose to glucose. It has also been shown that enzymatic hydrolysis could be greatly enhanced when the lignocellulosic structure is disrupted. Alkaline H202, ozone, organosolv (uses Lewis acids, FeCI3, (AI)2S04 in aqueous alcohols), glycerol, dioxane, phenol, or ethylene glycol are among solvents known to disrupt cellulose structure and promote hydrolysis (Mosier et al., 2005, Bioresource Technology 96: 673-686).
Alkaline chemical pre-treatment with base, e.g., NaOH, Na2C03 and/or ammonia or the like, is also within the scope of the invention. Pre-treatment methods using ammonia are described in, e.g., WO 2006/1 10891 , WO 2006/1 10899, WO 2006/1 10900, WO 2006/1 10901 , which are hereby incorporated by reference.
Wet oxidation techniques involve use of oxidizing agents, such as: sulphite based oxidizing agents or the like. Examples of solvent pre-treatments include treatment with DMSO (Dimethyl Sulfoxide) or the like. Chemical pre-treatment is generally carried out for 1 to 60 minutes, such as from 5 to 30 minutes, but may be carried out for shorter or longer periods of time dependent on the material to be pre-treated.
Other examples of suitable pre-treatment methods are described by Schell et al., 2003, Appl. Biochem and Biotechn. Vol. 105-108, p. 69-85, and Mosier et al., 2005, Bioresource Technology 96: 673-686, and US publication no. 2002/0164730, which references are hereby all incorporated by reference.
Mechanical Pre-treatment
As used in context of the present invention the term "mechanical pre-treatment" refers to any mechanical or physical pre-treatment which promotes the separation and/or release of cellulose, hemicellulose and/or lignin from lignocellulose-containing material. For example, mechanical pre-treatment includes various types of milling, irradiation, steaming/steam explosion, and hydrothermolysis.
Mechanical pre-treatment includes comminution (mechanical reduction of the particle size). Comminution includes dry milling, wet milling and vibratory ball milling. Mechanical pre- treatment may involve high pressure and/or high temperature (steam explosion). In an embodiment of the invention high pressure means pressure in the range from 300 to 600 psi, preferably 400 to 500 psi, such as around 450 psi. In an embodiment of the invention high temperature means temperatures in the range from about 100 to 300°C, preferably from about 140 to 235°C. In a preferred embodiment mechanical pre-treatment is a batch-process, steam gun hydrolyzer system which uses high pressure and high temperature as defined above. A Sunds Hydrolyzer (available from Sunds Defibrator AB (Sweden) may be used for this.
Combined Chemical and Mechanical Pre-treatment
In an embodiment of the invention both chemical and mechanical pre-treatments are carried out involving, for example, both dilute or mild acid pretreatment and high temperature and pressure treatment. The chemical and mechanical pretreatment may be carried out sequentially or simultaneously, as desired.
Accordingly, in a preferred embodiment, the lignocellulose-containing material is subjected to both chemical and mechanical pre-treatment to promote the separation and/or release of cellulose, hemicellulose and/or lignin.
In a preferred embodiment pre-treatment is carried out as a dilute or mild acid pretreatment step. In another preferred embodiment pre-treatment is carried out as an ammonia fiber explosion step (or AFEX pre-treatment step). Biological Pre-treatment
As used in the present invention the term "biological pre-treatment" refers to any biological pre-treatment which promotes the separation and/or release of cellulose, hemicellulose, and/or lignin from the lignocellulose-containing material. Biological pre-treatment techniques can involve applying lignin-solubilizing microorganisms (see, for example, Hsu, T.-A., 1996, Pretreatment of biomass, in Handbook on Bioethanol: Production and Utilization, Wyman, C. E., ed., Taylor & Francis, Washington, DC, 179-212; Ghosh, P., and Singh, A., 1993, Physicochemical and biological treatments for enzymatic/microbial conversion of lignocellulosic biomass, Adv. Appl. Microbiol. 39: 295-333; McMillan, J. D., 1994, Pretreating lignocellulosic biomass: a review, in Enzymatic Conversion of Biomass for Fuels Production, Himmel, M. E., Baker, J. O., and Overend, R. P., eds., ACS Symposium Series 566, American Chemical Society, Washington, DC, chapter 15; Gong, C. S., Cao, N. J., Du, J., and Tsao, G. T., 1999, Ethanol production from renewable resources, in Advances in Biochemical Engineering/Biotechnology, Scheper, T., ed., Springer-Verlag Berlin Heidelberg, Germany, 65: 207-241 ; Olsson, L, and Hahn-Hagerdal, B., 1996, Fermentation of lignocellulosic hydrolysates for ethanol production, Enz. Microb. Tech. 18: 312-331 ; and Vallander, L, and Eriksson, K.-E. L, 1990, Production of ethanol from lignocellulosic materials: State of the art, Adv. Biochem. Eng./Biotechnol. 42: 63-95).
Hydrolysis
Before and/or during fermentation the pre-treated lignocellulose-containing material may be hydrolyzed in order to break the lignin seal and disrupt the crystalline structure of cellulose. In a preferred embodiment hydrolysis is carried out enzymatically. According to the invention the pre-treated lignocellulose-containing material to be fermented may be hydrolyzed by one or more hydrolases (class E.C. 3 according to Enzyme Nomenclature), preferably one or more carbohydrases including cellulolytic enzymes and hemicellulolytic enzymes, or combinations thereof. Further, protease, alpha-amylase, glucoamylase and/or the like may also be present during hydrolysis and/or fermentation as the lignocellulose-containing material may include some, e.g., starchy and/or proteinaceous material.
The enzyme(s) used for hydrolysis may be capable of directly or indirectly converting carbohydrate polymers into fermentable sugars, such as glucose and/or maltose, which can be fermented into a desired fermentation product, such as ethanol.
In a preferred embodiment the carbohydrase(s) has(have) cellulolytic and/or hemicellulolytic enzyme activity.
In a preferred embodiment hydrolysis is carried out using a cellulolytic enzyme composition further comprising one or more polypeptides having cellulolytic enhancing activity.
In a preferred embodiment the polypeptide(s) having cellulolytic enhancing activity is of family GH61 origin. Examples of suitable and preferred cellulolytic enzyme compositions and polypeptides having cellulolytic enhancing activity are described in the "Cellulases or Cellulolytic Enzyme Polypeptides' -section and "Cellulolytic Enhancing Polypeptides" sections below.
Suitable enzymes are described in the "Enzymes" section below. Hemicellulose polymers can be broken down by hemicellullolytic enzymes and/or acid hydrolysis to release its five and six carbon sugar components. The six carbon sugars (hexoses), such as glucose, galactose, arabinose, and mannose, can readily be fermented to fermentation products such as ethanol, acetone, butanol, glycerol, citric acid, fumaric acid, etc. by suitable fermenting organisms including yeast.
Yeast is the preferred fermenting organism for ethanol fermentation. Preferred are strains of Saccharomyces, especially strains of the species Saccharomyces cerevisiae, preferably strains which are resistant towards high levels of ethanol, i.e., up to, e.g., about 10, 12, 15 or 20 vol. % or more ethanol.
Enzymatic hydrolysis is preferably carried out in a suitable aqueous environment under conditions which can readily be determined by one skilled in the art. In a preferred embodiment hydrolysis is carried out at suitable, preferably optimal, conditions for the enzyme(s) in question.
Suitable process time, temperature and pH conditions can readily be determined by one skilled in the art. Preferably, hydrolysis is carried out at a temperature between 25 and 70°C, preferably between 40 and 60°C, especially around 50°C. The step is preferably carried out at a pH in the range from 3-8, preferably pH 4-6. Hydrolysis is typically carried out for between 12 and 96 hours, preferable 16 to 72 hours, more preferably between 24 and 48 hours.
Fermentation of Lignocellulose derived Material
Fermentation of lignocellulose derived material is carried out in accordance with a fermentation process of the invention as described above, wherein chondroitin sulphate is present in fermentation and/or added before and/or during fermentation.
Lignocellulose-Containing Material (Biomass)
Any suitable lignocellulose-containing material is contemplated in context of the present invention. Lignocellulose-containing material may be any material containing lignocellulose. In a preferred embodiment the lignocellulose-containing material contains at least 50 wt. %, preferably at least 70 wt. %, more preferably at least 90 wt. % lignocellulose. It is to be understood that the lignocellulose-containing material may also comprise other constituents such as cellulosic material, such as cellulose, hemicellulose and may also comprise constituents such as sugars, such as fermentable sugars and/or un-fermentable sugars.
Lignocellulose-containing material is generally found, for example, in the stems, leaves, hulls, husks, and cobs of plants or leaves, branches, and wood of trees. Lignocellulosic material can also be, but is not limited to, herbaceous material, agricultural residues, forestry residues, municipal solid wastes, waste paper, and pulp and paper mill residues. It is understood herein that lignocellulose-containing material may be in the form of plant cell wall material containing lignin, cellulose, and hemi-cellulose in a mixed matrix.
In an embodiment the lignocellulose-containing material is corn fiber, rice straw, pine wood, wood chips, poplar, wheat straw, switchgrass, bagasse, paper and pulp processing waste.
Other more specific examples include corn stover, corn cobs, corn fiber, hardwood such as poplar and birch, softwood, cereal straw such as wheat straw, switch grass, Miscanthus, rice hulls, municipal solid waste (MSW), industrial organic waste, office paper, or mixtures thereof.
In a preferred embodiment the lignocellulose-containing material is corn stover or corn cobs. In another preferred embodiment, the lignocellulose-containing material is corn fiber. In another preferred embodiment, the lignocellulose-containing material is switch grass. In another preferred embodiment, the lignocellulose-containing material is bagasse.
SSF, HHF and SHF
In one embodiment of the present invention, hydrolysis and fermentation is carried out as a simultaneous hydrolysis and fermentation step (SSF). In general this means that combined/simultaneous hydrolysis and fermentation are carried out at conditions (e.g., temperature and/or pH) suitable, preferably optimal, for the fermenting organism(s) in question.
In another embodiment hydrolysis step and fermentation step are carried out as hybrid hydrolysis and fermentation (HHF). HHF typically begins with a separate partial hydrolysis step and ends with a simultaneous hydrolysis and fermentation step. The separate partial hydrolysis step is an enzymatic cellulose saccharification step typically carried out at conditions (e.g., at higher temperatures) suitable, preferably optimal, for the hydrolyzing enzyme(s) in question. The subsequent simultaneous hydrolysis and fermentation step is typically carried out at conditions suitable for the fermenting organism(s) (often at lower temperatures than the separate hydrolysis step).
In another embodiment, the hydrolysis and fermentation steps may be carried out as separate hydrolysis and fermentation, where the hydrolysis is taken to completion before initiation of fermentation. This is often referred to as "SHF". Enzymes
Even if not specifically mentioned in context of a process of the invention, it is to be understood that the enzyme(s) is used in an "effective amount". Alpha-Amylase
According to the invention an alpha-amylase may be used any alpha-amylase. In a preferred embodiment the alpha-amylase is an acid alpha-amylase, e.g., fungal acid alpha- amylase or bacterial acid alpha-amylase. The term "acid alpha-amylase" means an alpha- amylase (E.C. 3.2.1 .1 ) which added in an effective amount has activity optimum at a pH in the range of 3 to 7, preferably from 3.5 to 6, or more preferably from 4-5.
Bacterial Alpha-Amylase
The term "bacterial alpha-amylase" means any bacterial alpha-amylase classified under EC 3.2.1 .1. A bacterial alpha-amylase used according to the invention may, e.g., be derived from a strain of the genus Bacillus, which is sometimes also referred to as the genus Geobacillus. In an embodiment the Bacillus alpha-amylase is derived from a strain of Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus stearothermophilus, Bacillus sp. TS-23, or Bacillus subtilis, but may also be derived from other Bacillus sp. Specific examples of bacterial alpha-amylases include the Bacillus stearothermophilus alpha-amylase of SEQ ID NO: 3 in WO 99/19467, the Bacillus amyloliquefaciens alpha-amylase of SEQ ID NO: 5 in WO 99/19467, and the Bacillus licheniformis alpha-amylase of SEQ ID NO: 4 in WO 99/19467 and the Bacillus sp. TS-23 alpha-amylase disclosed as SEQ ID NO: 1 in WO 2009/061380 (all sequences are hereby incorporated by reference). In an embodiment the bacterial alpha-amylase may be an enzyme having a degree of identity of at least 60%, e.g., at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% to any of the sequences shown in SEQ ID NOS: 3, 4 or 5, respectively, in WO 99/19467 and SEQ ID NO: 1 in WO 2009/061380. In an embodiment the alpha-amylase may be an enzyme having a degree of identity of at least 60%, e.g., at least 70%, at least 80%, at least 90%, at least 91 %, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% to any of the sequences shown in SEQ ID NO: 3 in WO 99/19467. In a preferred embodiment the alpha-amylase is derived from Bacillus stearothermophilus. The Bacillus stearothermophilus alpha-amylase may be a mature wild-type or a mature variant thereof. The mature Bacillus stearothermophilus alpha-amylases, or variant thereof, may be naturally truncated during recombinant production. For instance, the mature Bacillus stearothermophilus alpha-amylase may be a truncated so it has around 491 amino acids (compared to SEQ ID NO: 3 in WO 99/19467), such as from 480-495 amino acids. The Bacillus alpha-amylase may also be a variant and/or hybrid. Examples of such a variant can be found in any of WO 96/23873, WO 96/23874, WO 97/41213, WO 99/19467, WO 00/60059, WO 02/10355 and WO2009/061380 (all documents are hereby incorporated by reference). Specific alpha-amylase variants are disclosed in U.S. Patent Nos. 6,093,562, 6,187,576, 6,297,038, and 7,713,723 (hereby incorporated by reference) and include Bacillus stearothermophilus alpha-amylase (often referred to as BSG alpha-amylase) variants having a deletion of one or two amino acids at positions R179, G180, 1181 and/or G182, preferably a double deletion disclosed in WO 96/23873 - see, e.g., page 20, lines 1 -10 (hereby incorporated by reference), preferably corresponding to deletion of positions 1181 and G182 compared to the amino acid sequence of Bacillus stearothermophilus alpha-amylase set forth in SEQ ID NO: 3 disclosed in WO 99/19467 or the deletion of amino acids R179 and G180 using SEQ ID NO: 3 in WO 99/19467 (which reference is hereby incorporated by reference). Even more preferred are Bacillus alpha- amylases, especially Bacillus stearothermophilus alpha-amylases, which have a double deletion corresponding to a deletion of positions 181 and 182 and further comprise a N193F substitution (also denoted 1181 * + G182* + N193F) compared to the wild-type BSG alpha-amylase amino acid sequence set forth in SEQ ID NO: 3 disclosed in WO 99/19467. The bacterial alpha- amylase may also have a substitution in a position corresponding to S239 in the Bacillus licheniformis alpha-amylase shown in SEQ ID NO: 4 in WO 99/19467, or a S242 variant of the Bacillus stearothermophilus alpha-amylase of SEQ ID NO: 3 in WO 99/19467. In an embodiment the variant is a S242A, E or Q variant, preferably a S242Q variant, of the Bacillus stearothermophilus alpha-amylase. In an embodiment the variant is a position E188 variant, preferably E188P variant of the Bacillus stearothermophilus alpha-amylase.
Other contemplated variant are Bacillus sp. TS-23 variant disclosed in WO2009/061380, especially variants defined in claim 1 of WO2009/061380.
Bacterial Hybrid Alpha-Amylases
The bacterial alpha-amylase may also be a hybrid bacterial alpha-amylase, e.g., an alpha-amylase comprising 445 C terminal amino acid residues of the Bacillus licheniformis alpha-amylase (shown in SEQ ID NO: 4 of WO 99/19467) and the 37 N terminal amino acid residues of the alpha-amylase derived from Bacillus amyloliquefaciens (shown in SEQ ID NO: 5 of WO 99/19467). In a preferred embodiment this hybrid has one or more, especially all, of the following substitutions:
G48A+T49I+G107A+H156Y+A181T+N190F+I201 F+A209V+Q264S (using the Bacillus licheniformis numbering in SEQ ID NO: 4 of WO 99/19467). Also preferred are variants having one or more of the following mutations (or corresponding mutations in other Bacillus alpha- amylases): H154Y, A181 T, N190F, A209V and Q264S and/or the deletion of two residues between positions 176 and 179, preferably the deletion of E178 and G179 (using SEQ ID NO: 5 of WO 99/19467 for position numbering).
In an embodiment the bacterial alpha-amylase is the mature part of the chimeric alpha- amylase disclosed in Richardson et al., 2002, The Journal of Biological Chemistry 277(29):. 267501 -26507, referred to as BD5088 or a variant thereof. This alpha-amylase is the same as the one shown in SEQ ID NO: 2 in WO 2007134207. The mature enzyme sequence starts after the initial "Met" amino acid in position 1 .
In an embodiment the bacterial alpha-amylase is dosed in an amount of 0.0005-5 KNU per g DS (dry solids), preferably 0.001 -1 KNU per g DS, such as around 0.050 KNU per g DS.
Fungal Alpha-Amylase
Fungal alpha-amylases include alpha-amylases derived from a strain of the genus Aspergillus, such as, Aspergillus oryzae, Aspergillus niger and Aspergillis kawachii alpha- amylases.
A preferred acidic fungal alpha-amylase is a Fungamyl-like alpha-amylase which is derived from a strain of Aspergillus oryzae. According to the present invention, the term "Fungamyl-like alpha-amylase" indicates an alpha-amylase which exhibits a high identity, i.e., more than 70%, more than 75%, more than 80%, more than 85% more than 90%, more than 95%, more than 96%, more than 97%, more than 98%, more than 99% or even 100% identity to the mature part of the amino acid sequence shown in SEQ ID NO: 10 in WO 96/23874.
Another preferred acidic alpha-amylase is derived from a strain Aspergillus niger. In a preferred embodiment the acid fungal alpha-amylase is the one from A. niger disclosed as "AMYA_ASPNG" in the Swiss-prot/TeEMBL database under the primary accession no. P56271 and described in WO 89/01969 (Example 3). A commercially available acid fungal alpha- amylase derived from Aspergillus niger is SP288 (available from Novozymes A/S, Denmark). Other contemplated wild-type alpha-amylases include those derived from a strain of the genera Rhizomucor and Meripilus, preferably a strain of Rhizomucor pusillus (WO 2004/055178 incorporated by reference) or Meripilus giganteus.
In a preferred embodiment the alpha-amylase is derived from Aspergillus kawachii and disclosed by Kaneko et al., 1996, J. Ferment Bioeng. 81 : 292-298, "Molecular-cloning and determination of the nucleotide-sequence of a gene encoding an acid-stable alpha-amylase from Aspergillus kawachir; and further as EMBL:#AB008370.
The fungal alpha-amylase may also be a wild-type enzyme comprising a starch-binding domain (SBD) and an alpha-amylase catalytic domain (i.e., non-hybrid), or a variant thereof. In an embodiment the wild-type alpha-amylase is derived from a strain of Aspergillus kawachii.
Fungal Hybrid Alpha-Amylase
In a preferred embodiment the fungal acid alpha-amylase is a hybrid alpha-amylase. Preferred examples of fungal hybrid alpha-amylases include the ones disclosed in WO 2005/00331 1 or U.S. application publication no. 2005/0054071 (Novozymes) or U.S. application no. 60/638,614 (Novozymes) which is hereby incorporated by reference. A hybrid alpha- amylase may comprise an alpha-amylase catalytic domain (CD) and a carbohydrate-binding domain/module (CBM), such as a starch binding domain, and optional a linker.
Specific examples of contemplated hybrid alpha-amylases include those disclosed in Table 1 to 5 of the examples in U.S. application no. 60/638,614, including Fungamyl variant with catalytic domain JA1 18 and Athelia rolfsii SBD (SEQ ID NO:100 in US 60/638,614), Rhizomucor pusillus alpha-amylase with Athelia rolfsii AMG linker and SBD (SEQ ID NO:101 in US 60/638,614), Rhizomucor pusillus alpha-amylase with Aspergillus niger glucoamylase linker and SBD (which is disclosed in Table 5 as a combination of amino acid sequences SEQ ID NO: 20, SEQ ID NO: 72 and SEQ ID NO: 96 in U.S. application no. 1 1/316,535) or as V039 in Table 5 in WO 2006/069290, and Meripilus giganteus alpha-amylase with Athelia rolfsii glucoamylase linker and SBD (SEQ ID NO: 102 in U.S. application no. 60/638,614). Other specifically contemplated hybrid alpha-amylases are any of the ones listed in Tables 3, 4, 5, and 6 in Example 4 in U.S. application no. 1 1/316,535 and WO 2006/069290 (hereby incorporated by reference).
Other specific examples of contemplated hybrid alpha-amylases include those disclosed in U.S. application publication no. 2005/0054071 , including those disclosed in Table 3 on page 15, such as Aspergillus niger alpha-amylase with Aspergillus awachii linker and starch binding domain.
Contemplated are also alpha-amylases which exhibit a high identity to any of above mention alpha-amylases, i.e., more than 70%, more than 75%, more than 80%, more than 85% more than 90%, more than 95%, more than 96%, more than 97%, more than 98%, more than 99% or even 100% identity to the mature enzyme sequences.
An acid alpha-amylases may according to the invention be added in an amount of 0.1 to 10 AFAU/g DS, preferably 0.10 to 5 AFAU/g DS, especially 0.3 to 2 AFAU/g DS or 0.001 to 1 FAU-F/g DS, preferably 0.01 to 1 FAU-F/g DS.
Commercial Alpha-Amylase Products
Preferred commercial compositions comprising alpha-amylase include MYCOLASE from DSM (Gist Brocades), BAN™, TERMAMYL™ SC, FUNGAMYL™, LIQUOZYME™ X and SAN™ SUPER, SAN™ EXTRA L (Novozymes MS) and CLARASE™ L-40,000, DEX-LO™, SPEZYME™ FRED, SPEZYME™ AA, SPEZYME™ DELTA AA, SPEZYME XTRA™ (Genencor Int., USA), FUELZYME™ (from Verenium Corp, USA) and the acid fungal alpha-amylase sold under the trade name SP288 (available from Novozymes A S, Denmark).
Carbohydrate-Source Generating Enzyme
The term "carbohydrate-source generating enzyme" includes glucoamylase (being glucose generators), beta-amylase and maltogenic amylase (being maltose generators). A carbohydrate-source generating enzyme is capable of producing a carbohydrate that can be used as an energy-source by the fermenting organism(s) in question, for instance, when used in a process of the invention for producing a fermentation product, such as ethanol. The generated carbohydrate may be converted directly or indirectly to the desired fermentation product, preferably ethanol. According to the invention a mixture of carbohydrate-source generating enzymes may be used. Especially contemplated mixtures are mixtures of at least a glucoamylase and an alpha-amylase, especially an acid amylase, even more preferred an acid fungal alpha-amylase. The ratio between acid fungal alpha-amylase activity (AFAU) per glucoamylase activity (AGU) (AFAU per AGU) may in an embodiment of the invention be at least 0.1 , or at least 0.16, such as in the range from 0.12 to 0.50 or more. The ratio between acid fungal alpha-amylase activity (FAU-F) and glucoamylase activity (AGU) {i.e., FAU-F per AGU) may in an embodiment of the invention be between 0.1 and 100, in particular between 2 and 50, such as in the range from 10-40. Glucoamylase
A glucoamylase used according to the invention may be derived from any suitable source, e.g., derived from a microorganism or a plant. Preferred glucoamylases are of fungal or bacterial origin, selected from the group consisting of Aspergillus glucoamylases, in particular A. niger G1 or G2 glucoamylase (Boel et al., 1984, EMBO J. 3 (5): 1097-1 102), or variants thereof, such as those disclosed in WO 92/00381 , WO 00/04136 and WO 01/04273 (from Novozymes, Denmark); the A. awamori glucoamylase disclosed in WO 84/02921 , A. oryzae glucoamylase (Agric. Biol. Chem. , 1991 , 55 (4): 941-949), or variants or fragments thereof. Other Aspergillus glucoamylase variants include variants with enhanced thermal stability: G137A and G139A (Chen et al., 1996, Prot. Eng. 9: 499-505); D257E and D293E/Q (Chen et al., 1995, Prot. Eng. 8: 575-582); N182 (Chen et al., 1994, Biochem. J. 301 : 275-281 ); disulphide bonds, A246C (Fierobe et al., 1996, Biochemistry 35: 8698-8704; and introduction of Pro residues in position A435 and S436 (Li et al., 1997, Protein Eng. 10: 1 199-1204.
Other glucoamylases include Athelia rolfsii (previously denoted Corticium rolfsii) glucoamylase (see U.S. Patent No. 4,727,026 and Nagasaka et al., 1998, "Purification and properties of the raw-starch-degrading glucoamylases from Corticium rolfsii, AppI Microbiol Biotechnol 50:323-330), Talaromyces glucoamylases, in particular derived from Talaromyces emersonii (WO 99/28448), Talaromyces leycettanus (U.S. Patent No. Re. 32,153), Talaromyces duponti, and Talaromyces thermophilus (U.S. Patent No. 4,587,215).
Bacterial glucoamylases contemplated include glucoamylases from the genus Clostridium, in particular C. thermoamylolyticum (EP 135,138), and C. thermohydrosulfuricum (WO 86/01831 ).
Contemplated fungal glucoamylases include Trametes cingulate (SEQ ID NO: 2), Pachykytospora papyracea; and Leucopaxillus giganteus all disclosed in WO 2006/069289; and Peniophora rufomarginata disclosed in WO2007/124285; or a mixture thereof. Also hybrid glucoamylase are contemplated according to the invention. Examples include the hybrid glucoamylases disclosed in WO 2005/045018. Specific examples include the hybrid glucoamylase disclosed in Table 1 and 4 of Example 1 (which hybrids are hereby incorporated by reference). In an embodiment the glucoamylase is derived from a strain of the genus Pycnoporus, in particular a strain of Pycnoporus as described in WO 201 1/066576 (SEQ ID NOs 2, 4 or 6), or from a strain of the genus Gloephyllum, in particular a strain of Gloephyllum as described in WO 201 1/068803 (SEQ ID NO: 2, 4, 6, 8, 10, 12, 14 or 16) or a strain of the genus Nigrofomes, in particular a strain of Nigrofomes sp. disclosed in WO 2012/064351 (SEQ ID NO: 2) (all references hereby incorporated by reference). Contemplated are also glucoamylases which exhibit a high identity to any of the above-mentioned glucoamylases, i.e., at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, such as 100% identity to any one of the mature parts of the enzyme sequences mentioned above.
Commercially available compositions comprising glucoamylase include AMG 200L; AMG 300 L; SAN™ SUPER, SAN™ EXTRA L, SPIRIZYME™ PLUS, SPI RIZYME™ FUEL, SPIRIZYME™ B4U, SPIRIZYME ULTRA™ and AMG™ E (from Novozymes A/S, Denmark); OPTIDEX™ 300, GC480™ and GC147™ (from Genencor Int., USA); AMIGASE™ and AMIGASE™ PLUS (from DSM); G-ZYME™ G900, G-ZYME™ and G990 ZR (from Genencor Int.).
Glucoamylases may in an embodiment be added in an amount of 0.02-20 AGU/g DS, preferably 0.1 -10 AGU/g DS, especially between 1-5 AGU/g DS, such as 0.1 -2 AGU/g DS, such as 0.5 AGU/g DS or in an amount of 0.0001-20 AGU/g DS, preferably 0.001-10 AGU/g DS, especially between 0.01 -5 AGU/g DS, such as 0.1-2 AGU/g DS.
Beta-Amylase
At least according to the invention the a beta-amylase (E.C 3.2.1.2) is the name traditionally given to exo-acting maltogenic amylases, which catalyze the hydrolysis of 1 ,4- alpha-glucosidic linkages in amylose, amylopectin and related glucose polymers. Maltose units are successively removed from the non-reducing chain ends in a step-wise manner until the molecule is degraded or, in the case of amylopectin, until a branch point is reached. The maltose released has the beta anomeric configuration, hence the name beta-amylase.
Beta-amylases have been isolated from various plants and microorganisms (W.M. Fogarty and C.T. Kelly, 1979, Progress in Industrial Microbiology 15: 1 12-1 15). These beta- amylases are characterized by having optimum temperatures in the range from 40°C to 65°C and optimum pH in the range from 4.5 to 7. A commercially available beta-amylase from barley is NOVOZYM™ WBA from Novozymes A/S, Denmark and SPEZYME™ BBA 1500 from Genencor Int., USA.
Maltogenic amylase
The amylase may also be a maltogenic alpha-amylase. A "maltogenic alpha-amylase"
(glucan 1 ,4-alpha-maltohydrolase, E.C. 3.2.1.133) is able to hydrolyze amylose and amylopectin to maltose in the alpha-configuration. A maltogenic amylase from Bacillus stearothermophilus strain NCIB 1 1837 is commercially available from Novozymes A/S. Maltogenic alpha-amylases are described in U.S. Patent Nos. 4,598,048, 4,604,355 and 6,162,628, which are hereby incorporated by reference.
The maltogenic amylase may in a preferred embodiment be added in an amount of 0.05- 5 mg total protein/gram DS or 0.05- 5 MANU/g DS.
Proteases
A protease used in accordance with the present invention may be any protease, such as of microbial or plant origin. In a preferred embodiment the protease is an acid protease of microbial origin, preferably of fungal or bacterial origin.
Suitable proteases include microbial proteases, such as fungal and bacterial proteases. Preferred proteases are acidic proteases, i.e., proteases characterized by the ability to hydrolyze proteins under acidic conditions below pH 7.
Contemplated acid fungal proteases include fungal proteases derived from Aspergillus, Mucor, Rhizopus, Candida, Coriolus, Endothia, Enthomophtra, Irpex, Penicillium, Sclerotiumand Torulopsis. Especially contemplated are proteases derived from Aspergillus niger (see, e.g., Koaze et al., 1964, Agr. Biol. Chem. Japan 28: 216), Aspergillus saitoi (see, e.g., Yoshida, 1954, J. Agr. Chem. Soc. Japan 28: 66), Aspergillus awamori (Hayashida et al., 1977, Agric. Biol. Chem. 42(5): 927-933, Aspergillus aculeatus (WO 95/02044), or Aspergillus oryzae, such as the pepA protease; and acidic proteases from Mucor pusillus or Mucor miehei.
Contemplated are also neutral or alkaline proteases, such as a protease derived from a strain of Bacillus. A particular protease contemplated for the invention is derived from Bacillus amyloliquefaciens and has the sequence obtainable at Swissprot as Accession No. P06832.
Also contemplated are the proteases having at least 90% identity to amino acid sequence obtainable at Swissprot as Accession No. P06832 such as at least 92%, at least 95%, at least 96%, at least 97%, at least 98%, or particularly at least 99% identity. Further contemplated are the proteases having at least 90% identity to amino acid sequence disclosed as SEQ.ID.NO: 1 in the WO 2003/048353 such as at 92%, at least 95%, at least 96%, at least 97%, at least 98%, or particularly at least 99% identity.
Also contemplated are papain-like proteases such as proteases within E.C. 3.4.22.* (cysteine protease), such as EC 3.4.22.2 (papain), EC 3.4.22.6 (chymopapain), EC 3.4.22.7 (asclepain), EC 3.4.22.14 (actinidain), EC 3.4.22.15 (cathepsin L), EC 3.4.22.25 (glycyl endopeptidase) and EC 3.4.22.30 (caricain).
In an embodiment the protease is a protease preparation derived from a strain of Aspergillus, such as Aspergillus oryzae. In another embodiment the protease is derived from a strain of Rhizomucor, preferably Rhizomucor miehei. In another contemplated embodiment the protease is a protease preparation, preferably a mixture of a proteolytic preparation derived from a strain of Aspergillus, such as Aspergillus oryzae, and a protease derived from a strain of Rhizomucor, preferably Rhizomucor mehei.
Aspartic acid proteases are described in, for example, Handbook of Proteolytic Enzymes, Edited by Barrett, Rawlings and Woessner, Academic Press, San Diego, 1998, Chapter 270). Suitable examples of aspartic acid protease include, e.g., those disclosed in Berka et al., 1990, Gene 96: 313; Berka et al., 1993, Gene 125: 195-198; and Gomi et al., 1993, Biosci. Biotech. Biochem. 57: 1095-1 100, which are hereby incorporated by reference.
Commercially available products include ALCALASE®, ESPERASE™, FLAVOURZYME™, PROMIX™, NEUTRASE®, RENNILASE®, NOVOZYM™ FM 2.0L, and NOVOZYM™ 50006 (available from Novozymes A/S, Denmark) and GC106™ and SPEZYME™ FAN from Genencor Int., Inc., USA.
The protease may be present in an amount of 0.0001 -1 mg enzyme protein per g DS, preferably 0.001 to 0.1 mg enzyme protein per g DS. Alternatively, the protease may be present in an amount of 0.0001 to 1 LAPU/g DS, preferably 0.001 to 0.1 LAPU/g DS and/or 0.0001 to 1 mAU-RH/g DS, preferably 0.001 to 0.1 mAU-RH/g DS or 0.1 -1000 AU/kg DM (dry matter), preferably 1-100 AU/kg DS and most preferably 5-25 AU/kg DS.
Cellulases or Cellulolytic Enzymes
The terms "cellulases" or "cellulolytic enzymes" as used herein are understood as comprising the cellobiohydrolases (EC 3.2.1.91 ), e.g., cellobiohydrolase I and cellobiohydrolase II, as well as the endo-glucanases (EC 3.2.1 .4) and beta-glucosidases (EC 3.2.1.21 ). See relevant sections below with further description of such enzymes. In order to be efficient, the digestion of cellulose may require several types of enzymes acting cooperatively. At least three categories of enzymes are often needed to convert cellulose into glucose: endoglucanases (EC 3.2.1 .4) that cut the cellulose chains at random; cellobiohydrolases (EC 3.2.1 .91 ) which cleave cellobiosyl units from the cellulose chain ends and beta-glucosidases (EC 3.2.1.21 ) that convert cellobiose and soluble cellodextrins into glucose. Among these three categories of enzymes involved in the biodegradation of cellulose, cellobiohydrolases are the key enzymes for the degradation of native crystalline cellulose. The term "cellobiohydrolase I" is defined herein as a cellulose 1 ,4-beta-cellobiosidase (also referred to as Exo-glucanase, Exo-cellobiohydrolase or 1 ,4-beta-cellobiohydrolase) activity, as defined in the enzyme class EC 3.2.1.91 , which catalyzes the hydrolysis of 1 ,4-beta-D-glucosidic linkages in cellulose and cellotetraose, by the release of cellobiose from the non-reducing ends of the chains. The definition of the term "cellobiohydrolase II activity" is identical, except that cellobiohydrolase II attacks from the reducing ends of the chains.
The cellulases may comprise a carbohydrate-binding module (CBM) which enhances the binding of the enzyme to a cellulose-containing fiber and increases the efficacy of the catalytic active part of the enzyme. A CBM is defined as contiguous amino acid sequence within a carbohydrate-active enzyme with a discreet fold having carbohydrate-binding activity. For further information of CBMs see the CAZy internet server (Supra) or Tomme et al. (1995) in Enzymatic Degradation of Insoluble Polysaccharides (Saddler and Penner, eds.), Cellulose- binding domains: classification and properties, pp. 142-163, American Chemical Society, Washington.
In a preferred embodiment the cellulases or cellulolytic enzymes may be a cellulolytic preparation as defined in WO 2008/151079 or WO 2013/028928, which are both hereby incorporated by reference. In a preferred embodiment the cellulolytic preparation comprising a polypeptide having cellulolytic enhancing activity (GH61A), preferably the one disclosed in WO 2005/074656. The cellulolytic preparation may further comprise a beta-glucosidase, such as a beta-glucosidase derived from a strain of the genus Trichoderma, Aspergillus, or Penicillium, including the fusion protein having beta-glucosidase activity disclosed in WO 2008/057637 (Novozymes). In an embodiment the cellulolytic preparation may also comprises a CBH II, preferably Thielavia terrestris cellobiohydrolase II (CEL6A). In an embodiment the cellulolytic preparation also comprises a cellulase enzymes preparation, preferably the one derived from Trichoderma reesei. The cellulolytic activity may, in a preferred embodiment, be derived from a fungal source, such as a strain of the genus Trichoderma, preferably a strain of Trichoderma reeser, or a strain of the genus Humicola, such as a strain of Humicola insolens.
In an embodiment the cellulolytic enzyme preparation comprises a polypeptide having cellulolytic enhancing activity (GH61A) disclosed in WO 2005/074656; a cellobiohydrolase, such as Thielavia terrestris cellobiohydrolase II (CEL6A), a beta-glucosidase (e.g., the fusion protein disclosed in WO 2008/057637 and cellulolytic enzymes, e.g., derived from Trichoderma reesei.
In an embodiment the cellulolytic enzyme preparation comprises a polypeptide having cellulolytic enhancing activity (GH61A) disclosed in WO 2005/074656; a beta-glucosidase (e.g., the fusion protein disclosed in WO 2008/057637 and cellulolytic enzymes, e.g., derived from Trichoderma reesei.
In an embodiment the cellulolytic enzyme composition is a Trichoderma reesei cellulolytic enzyme composition, further comprising Thermoascus aurantiacus GH61A polypeptide having cellulolytic enhancing activity (SEQ ID NO: 2 in WO 2005/074656) and Aspergillus fumigatus beta-glucosidase (SEQ ID NO: 2 of WO 2005/047499).
In an embodiment the cellulolytic enzyme composition is a Trichoderma reesei cellulolytic enzyme composition further comprising Penicillium emersonii GH61A polypeptide disclosed as SEQ ID NO: 2 in WO 201 1/041397, and Aspergillus fumigatus beta-glucosidase disclosed as SEQ ID NO: 2 in WO 2005/047499, or a variant thereof, which variant has one of, preferably all of, the following substitutions: F100D, S283G, N456E, F512Y. In an embodiment the cellulolytic enzyme composition further comprises a cellobiohydrolase I and cellobiohydrolase II derived from Aspergillus fumigatus. In a preferred embodiment the cellulolytic enzyme composition comprises the Aspergillus fumigatus Cel7A CBH I disclosed as SEQ ID NO: 6 in WO201 1/057140 and the Aspergillus fumigatus CBH II disclosed as SEQ ID NO: 18 in WO 201 1/057140.
The cellulolytic enzyme composition may also comprise some hemicellulase, such as up to 20% hemicellulase, such as up to 15%, such as up to 10%, such as xylanase and/or xylosidase, such as beta-xylosidase. In an embodiment the cellulolytic enzyme composition comprises Aspergillus fumigatus GH10 xylanase, such as the one disclosed as SEQ ID NO: 6 (Xyl III) in WO 2006/078256, and Aspergillus fumigatus beta-xylosidase, such as the one disclosed in WO 2013/028928 (Example 16 and 17).
In an embodiment the cellulolytic enzyme is the commercially available product CELLUCLAST® 1 .5L, CELLUZYME™, CELLIC CTEC™, CELLIC CTEC2™, CELLIC CTEC3™ (all available from Novozymes A S, Denmark), ACCELLERASE 1000™, ACCELLERASE 1500™, ACCELLERASE DUET™, ACCELLERASE TRIO™ (all available from DuPont, USA).
A cellulase or cellulolytic enzyme may be dosed in the range from 0.1-100 FPU per gram total solids (TS), preferably 0.5-50 FPU per gram TS, especially 1-20 FPU per gram TS.
Endoglucanase (EG)
Endoglucanases (EC No. 3.2.1 .4) catalyses endo hydrolysis of 1 ,4-beta-D-glycosidic linkages in cellulose, cellulose derivatives (such as carboxy methyl cellulose and hydroxy ethyl cellulose), lichenin, beta-1 ,4 bonds in mixed beta-1 ,3 glucans such as cereal beta-D-glucans or xyloglucans and other plant material containing cellulosic parts. The authorized name is endo- 1 ,4-beta-D-glucan 4-glucano hydrolase, but the abbreviated term endoglucanase is used in the present specification. Endoglucanase activity may be determined using carboxymethyl cellulose (CMC) hydrolysis according to the procedure of Ghose, 1987, Pure and Appl. Chem. 59: 257-268.
In a preferred embodiment endoglucanases may be derived from a strain of the genus
Trichoderma, preferably a strain of Trichoderma reesei; a strain of the genus Humicola, such as a strain of Humicola insolens; or a strain of Chrysosporium, preferably a strain of Chrysosporium lucknowense. Cellobiohvdrolase (CBH)
The term "cellobiohydrolase" means a 1 ,4-beta-D-glucan cellobiohydrolase (E.C. 3.2.1.91 ), which catalyzes the hydrolysis of 1 ,4-beta-D-glucosidic linkages in cellulose, cellooligosaccharides, or any beta-1 ,4-linked glucose containing polymer, releasing cellobiose from the reducing or non-reducing ends of the chain.
Examples of cellobiohydroloses are mentioned above including CBH I and CBH II from
Trichoderma reseei; Humicola insolens, Aspergillus fumigatus, and CBH II from Thielavia terrestris cellobiohydrolase (CELL6A). In a preferred embodiment the cellulolytic enzyme composition comprises the Aspergillus fumigatus Cel7A CBH I disclosed as SEQ ID NO: 6 in WO201 1/057140 and the Aspergillus fumigatus CBH II disclosed as SEQ ID NO: 18 in WO 201 1/057140.
Cellobiohydrolase activity may be determined according to the procedures described by Lever et al., 1972, Anal. Biochem. 47: 273-279 and by van Tilbeurgh et al., 1982, FEBS Letters 149: 152-156; van Tilbeurgh and Claeyssens, 1985, FEBS Letters 187: 283-288. The Lever et al. method is suitable for assessing hydrolysis of cellulose in corn stover and the method of van Tilbeurgh et al. is suitable for determining the cellobiohydrolase activity on a fluorescent disaccharide derivative. Beta-glucosidase
One or more beta-glucosidases (often referred to as "cellobiases") may be present during hydrolysis.
The term "beta-glucosidase" means a beta-D-glucoside glucohydrolase (E.C. 3.2.1.21 ), which catalyzes the hydrolysis of terminal non-reducing beta-D-glucose residues with the release of beta-D-glucose. For purposes of the present invention, beta-glucosidase activity is determined according to the basic procedure described by Venturi et al., 2002, J. Basic Microbiol. 42: 55-66, except different conditions were employed as described herein. One unit of beta-glucosidase activity is defined as 1 .0 μηιοΐβ of p-nitrophenol produced per minute at 50°C, pH 5 from 4 mM p-nitrophenyl-beta-D-glucopyranoside as substrate in 100 mM sodium citrate, 0.01 % TWEEN® 20.
In an embodiment the beta-glucosidase is of fungal origin, such as a strain of the genus Trichoderma, Aspergillus or Penicillium. In a preferred embodiment the beta-glucosidase is a derived from Trichoderma reesei, such as the beta-glucosidase encoded by the bgll gene (see Fig. 1 of EP 562,003). In another preferred embodiment the beta-glucosidase is derived from Aspergillus oryzae (recombinantly produced in Aspergillus oryzae according to WO 02/095014). In an preferred embodiment the beta-glucosidase is derived from Aspergillus fumigatus such as the one disclosed as SEQ ID NO: 2 in WO 2005/047499, or a variant thereof, which variant has one of, preferably all of, the following substitutions: F100D, S283G, N456E, F512Y. Cellulolytic Enhancing Polypeptides
The term "cellulolytic enhancing activity" is defined herein as a biological activity that enhances the hydrolysis of a lignocellulose derived material by proteins having cellulolytic activity. For purposes of the present invention, cellulolytic enhancing activity is determined by measuring the increase in reducing sugars or in the increase of the total of cellobiose and glucose from the hydrolysis of a lignocellulose derived material, e.g. , pre-treated lignocellulose- containing material by cellulolytic protein under the following conditions: 1 -50 mg of total protein/g of cellulose in PCS (pre-treated corn stover), wherein total protein is comprised of 80- 99.5% w/w cellulolytic protein/g of cellulose in PCS and 0.5-20% w/w protein of cellulolytic enhancing activity for 1 -7 day at 50°C compared to a control hydrolysis with equal total protein loading without cellulolytic enhancing activity (1-50 mg of cellulolytic protein/g of cellulose in PCS).
The polypeptides having cellulolytic enhancing activity enhance the hydrolysis of a lignocellulose derived material catalyzed by proteins having cellulolytic activity by reducing the amount of cellulolytic enzyme required to reach the same degree of hydrolysis preferably at least 0.1 -fold, more at least 0.2-fold, more preferably at least 0.3-fold, more preferably at least 0.4-fold, more preferably at least 0.5-fold, more preferably at least 1 -fold, more preferably at least 3-fold, more preferably at least 4-fold, more preferably at least 5-fold, more preferably at least 10-fold, more preferably at least 20-fold, even more preferably at least 30-fold, most preferably at least 50-fold, and even most preferably at least 100-fold.
In an embodiment the hydrolysis and/or fermentation is carried out in the presence of a cellulolytic enzyme in combination with a polypeptide having enhancing activity. In a preferred embodiment the polypeptide having enhancing activity is a family GH61A polypeptide. WO 2005/074647 discloses isolated polypeptides having cellulolytic enhancing activity and polynucleotides thereof from Thielavia terrestris. WO 2005/074656 discloses an isolated polypeptide having cellulolytic enhancing activity and a polynucleotide thereof from Thermoascus aurantiacus. U.S. Application Publication No. 2007/0077630 discloses an isolated polypeptide having cellulolytic enhancing activity and a polynucleotide thereof from Trichoderma reesei.
In an embodiment the cellulolytic enzyme composition comprising Thermoascus aurantiacus GH61A polypeptide having cellulolytic enhancing activity (SEQ ID NO: 2 in WO 2005/074656). In another preferred embodiment the cellulolytic enzyme composition comprising Penicillium emersonii GH61A polypeptide disclosed as SEQ ID NO: 2 in WO 201 1/041397,
Hemicellulolytic enzymes
Hemicellulose can be broken down by hemicellulases and/or acid hydrolysis to release its five and six carbon sugar components.
In an embodiment of the invention the lignocellulose derived material may be treated with one or more hemicellulases.
Any hemicellulase suitable for use in hydrolyzing hemicellulose, preferably into xylose, may be used. Preferred hemicellulases include xylanases, beta-xylosidase, arabinofuranosidases, acetyl xylan esterase, feruloyl esterase, glucuronidases, galactanase, endo-galactanase, mannases, endo or exo arabinases, exo-galactanses, pectinase, xyloglucanase, or mixtures of two or more thereof. Preferably, the hemicellulase for use in the present invention is an exo-acting hemicellulase, and more preferably, the hemicellulase is an exo-acting hemicellulase which has the ability to hydrolyze hemicellulose under acidic conditions of below pH 7, preferably pH 3-7.
In an embodiment the hemicellulase is a xylanase. In an embodiment the xylanase is of microbial origin, such as of fungal origin (e.g., Trichoderma, Meripilus, Humicola, Aspergillus, Fusarium) or from a bacterium (e.g., Bacillus). In a preferred embodiment the xylanase is derived from a filamentous fungus, preferably derived from a strain of Aspergillus, such as Aspergillus aculeatus or Aspergillus fumigatus; or a strain of Humicola, preferably Humicola lanuginosa. The xylanase may preferably be an endo-1 ,4-beta-xylanase, more preferably an endo-1 ,4-beta- xylanase of GH10 or GH1 1. In an embodiment the xylanase is an Aspergillus aculeatus GH10 xylanase, such as the one disclosed as SEQ ID NO: 2 (Xyl II) in WO W09421785.
In an embodiment the xylanase is an Aspergillus fumigatus GH10 xylanase, such as the one disclosed as SEQ ID NO: 6 (Xyl III) in WO 2006/078256.
In an embodiment the hemicellulase is a beta-xylosidase. In an embodiment the beta- xylosidase is an Aspergillus fumigatus beta-xylosidase, such as the one disclosed in WO 2013/028928 (Example 16 and 17). Examples of commercial xylanases include SHEARZYME™ and CELLIC HTEC™, CELLIC HTEC2™ CELLIC HTEC3™ from Novozymes A/S, Denmark.
Arabinofuranosidase (EC 3.2.1 .55) catalyzes the hydrolysis of terminal non-reducing alpha-L-arabinofuranoside residues in alpha-L-arabinosides.
Galactanase (EC 3.2.1.89), arabinogalactan endo-1 ,4-beta-galactosidase, catalyses the endohydrolysis of 1 ,4-D-galactosidic linkages in arabinogalactans.
Pectinase (EC 3.2.1 .15) catalyzes the hydrolysis of 1 ,4-alpha-D-galactosiduronic linkages in pectate and other galacturonans.
Xyloglucanase catalyzes the hydrolysis of xyloglucan.
The hemicellulase may be added in an amount effective to hydrolyze hemicellulose, such as, in amounts from about 0.001 to 0.5 wt.-% of total solids (TS), more preferably from about 0.05 to 0.5 wt.-% of TS.
Xylanases may be added in amounts of 0.001-1.0 g/kg DM (dry matter) substrate, preferably in the amounts of 0.005-0.5 g/kg DM substrate, and most preferably from 0.05-0.10 g/kg DM substrate. Composition
In this aspect the invention relates to a composition comprising chondroitin sulphate and further one or more enzymes and/or one or more fermenting organisms.
The composition of the invention may comprise an enzyme from the class of hydrolases (class EC 3 according to Enzyme Nomenclature). In an embodiment the enzyme is selected from the group consisting of cellulase, hemicellulase, protease, alpha-amylase, and glucoamylase, or a mixture thereof.
In a preferred embodiment the enzyme is a glucoamylase, such as one listed in the "Glucoamylase' -section above.
The composition may also comprise a fermenting organism, such as yeast or another fermenting organisms mentioned in the "Fermenting OrganisrrT'-section above.
Use
In this aspect the invention relates to the use of chondroitin sulphate for propagating fermenting organisms, such as yeast.
In invention also relates to the use of chondroitin sulphate in a fermentation process or a process of the invention.
The present invention is further described in the following numbered paragraphs:
1. A process of fermenting sugars derived from plant material into a fermentation product using a fermenting organism, wherein chondroitin sulphate is present or added before and/or during fermentation.
2. The process of paragraph 1 , wherein chondroitin sulphate is added in fermentation.
3. The process of any of paragraphs 1-2, wherein chondroitin sulphate is added before fermentation, such as in a pre-saccharification step.
4. The process of any of paragraphs 1-3, wherein the fermenting organism is yeast, filamentous fungus and/or a bacterium.
5. The process of any of paragraphs 1-4, wherein the fermenting organism is derived from a strain of Saccharomyces, such as Saccharomyces cerevisiae.
6. The process of any of paragraphs 1-5, wherein the sugars derived from plant material are derived from starch-containing material or lignocellulose-containing material, or a mixture thereof. 7. The process of any of paragraphs 1 -6, wherein chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01 -200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1-40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1 -25 mg/g mash, such as around 10 mg/g mash.
8. The process of any of paragraphs 1 -7, wherein the fermentation product is an alcohol, preferably ethanol, especially fuel ethanol, potable ethanol and/or industrial ethanol.
9. The process of any of paragraphs 1 -8, wherein chondroitin sulphate boosts the fermentation yield compared to a corresponding fermentation where no chondroitin sulphate is present and/or added.
10. A process of producing a fermentation product from starch-containing material comprising the steps of:
i) liquefying starch-containing material using an alpha-amylase;
ii) saccharifying the liquefied material using a carbohydrate-source generating enzyme;
iii) fermenting using a fermenting organism; wherein fermentation is carried out as defined in any of paragraphs 1 -9.
1 1 . The process of paragraph 10, further comprises, prior to the liquefaction step i), the steps of:
a) reducing the particle size of the starch-containing material, preferably by dry milling; b) forming a slurry comprising the starch-containing material and water.
12. The process of paragraphs 10 or 1 1 , wherein the temperature during liquefaction is above the initial gelatinization temperature of starch
13. The process of any of paragraphs 10-12, wherein in the range from 70-100°C, such as between 70-95°C, such as between 75-90°C, preferably between 80-90°C, such as around 85°C.
14. The process of any of paragraphs 10-13, wherein a jet-cooking step is carried out prior to liquefaction in step i).
15. The process of paragraph 14, wherein the jet-cooking is carried out at a temperature between 95-140°C, preferably 105-125°C, for 1-15 minutes, preferably for 3-10 minutes, especially around 5 minutes.
16. The process of any of paragraphs 10-15, wherein the pH during liquefaction is between 4.0- 6.5, such as 4.5-6.2, such as above 4.8-6.0, such as between 5.0-5.8. 17. The process of any of paragraphs 10-16, wherein steps ii) and iii) are carried out simultaneously or sequentially.
18. The process of any of paragraphs 10-17, wherein the alpha-amylase is of bacterial origin.
19. The process of paragraph 18, wherein the alpha-amylase is from the genus Bacillus, such as a strain of Bacillus stearothermophilus, in particular a variant of a Bacillus stearothermophilus alpha-amylase, such as the one shown in SEQ ID NO: 3 in WO 99/019467.
20. The process of paragraph 19, wherein the Bacillus stearothermophilus alpha-amylase or variant thereof is truncated, preferably to have around 491 amino acids, such as from 480-495 amino acids.
21 . The process of any of paragraphs 10-20, wherein the liquefied material, in step ii), is saccharified using a carbohydrate-source generating enzyme.
22. The process of any of paragraphs 10-21 , wherein the saccharification step ii) is carried out for from about 24 to about 72 hours.
23. The process of any of paragraphs 10-22, wherein the carbohydrate-source generating enzyme is added during pre-saccharification carried out before saccharification step ii) or simultaneous saccharification and fermentation (SSF).
24. The process of paragraphs 23, wherein pre-saccharification is done for 40-90 minutes at a temperature between 30-65°C, typically about 60°C.
25. The process of paragraph 24, wherein pre-saccharification is followed by saccharification during fermentation in simultaneous saccharification and fermentation ("SSF).
26. The process of paragraph 25, wherein saccharification is carried out at temperatures from 20-75°C, preferably from 40-70°C, typically around 60°C, and at a pH between 4 and 5, such as around pH 4.5.
27. The process of paragraph 26, wherein fermentation or SSF is carried out at a temperature from 25°C to 40°C, such as from 28°C to 36°C, such as from 30°C to 34°C, preferably around about 32°C.
28. The process of any of paragraphs 10-27, wherein fermentation is ongoing for 6 to 120 hours, in particular 24 to 96 hours.
29. The process of any of paragraphs 10-28, wherein the pH is between 3.5-5, in particular between 3.8 and 4.3.
30. The process of any of paragraphs 10-29, wherein the carbohydrate-source generating enzyme, preferably a glucoamylase, is present or added in presaccharification before saccharification step ii), in saccharification step ii), or simultaneous saccharification and fermentation steps ii) and iii).
31 . The process of any of paragraphs 10-30, wherein the carbohydrate-source generating enzyme is a glucoamylase of fungal origin, preferably from a stain of Aspergillus, preferably Aspergillus niger, Aspergillus awamori, or Aspergillus oryzae; or a strain of Trichoderma, preferably T. reesei; or a strain of Talaromyces, preferably T. emersonii, or a strain of Pycnoporus, or a strain of Gloephyllum, or a strain of the Nigrofomes.
32. The process of paragraph 31 , wherein the glucoamylase is derived from a strain of in particular derived from a strain of Talaromyces emersonii disclosed as SEQ ID NO: 34 in WO 99/28448.
33. The process of paragraph 32, wherein the glucoamylase is derived from a strain of Gloeophyllum, such as a strain of Gloeophyllum sepiarium or Gloeophyllum trabeum, such as one disclosed in WO 201 1/068803 as any of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14 or 16, preferably SEQ ID NO: 2 in WO 201 1/068803 in WO 201 1/068803.
34. The process of any of paragraphs 10-33, wherein the fermenting organism is yeast, filamentous fungus and/or a bacterium.
35. The process of any of paragraphs 10-34, wherein the fermenting organism is derived from a strain of Saccharomyces, such as Saccharomyces cerevisiae.
36. The process of producing a fermentation product from starch-containing material, comprising the steps of:
(a) saccharifying starch-containing material at a temperature below the initial gelatinization temperature of said starch-containing material,
(b) fermenting using a fermenting organism,
wherein fermentation is carried out as defined in any of paragraphs 1 -9.
37. The process of paragraph 36, wherein steps (a) and (b) are carried out simultaneously or sequentially.
38. The process of paragraph 36 or 37, wherein the saccharification or simultaneous saccharification and fermentation are carried out in using a carbohydrate-source generating enzyme selected from the group consisting of glucoamylase, beta-amylase, and maltogenic amylase, or a mixture thereof.
39. The process of any of paragraphs 36-38, wherein an alpha-amylase is present during saccharification and/or fermentation, preferably simultaneous saccharification and fermentation. 40. The process of any of paragraphs 36-39, wherein the starch-containing material is granular starch.
41 . A process of producing a fermentation product from lignocellulose-containing material, comprising the steps of:
(a) pre-treating lignocellulose-containing material;
(b) hydrolyzing the material;
(c) fermenting using a fermenting organism;
wherein fermentation is carried out as defined in any of paragraphs 1 -9.
42. The process of paragraphs 41 , wherein chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01-200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1-40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1 -25 mg/g mash, such as around 10 mg/g mash.
43. The process of paragraph 42, wherein the lignocellulose-containing material is chemically, mechanically and/or biologically pre-treated in step (a).
44. The process of any of paragraphs 41-43, wherein hydrolysis in step (b) and fermentation in step (c) is carried out as a SSF, HHF or SHF process.
45. The process of any of paragraphs 41 -44, wherein the fermenting organism is yeast, preferably a strain of the genus Saccharomyces or Pichia.
46. A composition comprising chondroitin sulphate and one or more enzymes and/or one or more fermenting organisms.
47. The composition of paragraph 46, wherein the enzyme(s) is one or more hydrolases (class EC 3 according to Enzyme Nomenclature) selected from the group consisting of cellulases, hemicellulases, proteases, alpha-amylases, glucoamylases, or a mixture thereof.
48. The composition of paragraph 46 or 47, wherein the fermenting organism is selected from the group of yeast, filamentous fungus and/or a bacteria.
49. Use of chondroitin sulphate for propagating fermenting organisms.
50. Use of chondroitin sulphate in a fermentation process.
The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. In the case of conflict, the present disclosure, including definitions will be controlling.
Various references are cited herein, the disclosures of which are incorporated by reference in their entireties.
MATERIALS & METHODS
Materials:
Chondroitin sulphate was sourced from Sigma Product# C9819-5G Glucoamylase E: Blend comprising Talaromyces emersonii glucoamylase disclosed as SEQ ID NO: 34 in W099/28448, Trametes cingulata glucoamylase disclosed as SEQ ID NO: 2 in WO 06/69289, and Rhizomucor pusillus alpha-amylase with Aspergillus niger glucoamylase linker and SBD disclosed as V039 in Table 5 in WO 2006/069290 (ratio about 75:20:5). Yeast:
- RED STAR™ available from Red Star/Lesaffre, USA
Methods:
Identity
The relatedness between two amino acid sequences or between two nucleotide sequences is described by the parameter "identity".
For purposes of the present invention, the degree of identity between two amino acid sequences is determined by the Clustal method (Higgins, 1989, CABIOS 5: 151-153) using the
LASERGENE™ MEGALIGN™ software (DNASTAR, Inc., Madison, Wl) with an identity table and the following multiple alignment parameters: Gap penalty of 10 and gap length penalty of
10. Pairwise alignment parameters are Ktuple=1 , gap penalty=3, windows=5, and diagonals=5.
For purposes of the present invention, the degree of identity between two nucleotide sequences is determined by the Wilbur-Lipman method (Wilbur and Lipman, 1983, Proceedings of the National Academy of Science USA 80: 726-730) using the LASERGENE™ MEGALIGN™ software (DNASTAR, Inc., Madison, Wl) with an identity table and the following multiple alignment parameters: Gap penalty of 10 and gap length penalty of 10. Pairwise alignment arameters are Ktuple=3, gap penalty=3, and windows=20. Glucoamylase activity (AGU)
The Novo Glucoamylase Unit (AGU) is defined as the amount of enzyme, which hydrolyzes 1 micromole maltose per minute under the standard conditions 37°C, pH 4.3, substrate: maltose 23.2 mM, buffer: acetate 0.1 M, reaction time 5 minutes.
An autoanalyzer system may be used. Mutarotase is added to the glucose dehydrogenase reagent so that any alpha-D-glucose present is turned into beta-D-glucose. Glucose dehydrogenase reacts specifically with beta-D-glucose in the reaction mentioned above, forming NADH which is determined using a photometer at 340 nm as a measure of the original glucose concentration.
Figure imgf000045_0001
Figure imgf000045_0002
A folder (EB-SM-0131.02/01 ) describing this analytical method in more detail is available on request from Novozymes A/S, Denmark, which folder is hereby included by reference. Alpha-amylase activity (KNU)
The alpha-amylase activity may be determined using potato starch as substrate. This method is based on the break-down of modified potato starch by the enzyme, and the reaction is followed by mixing samples of the starch/enzyme solution with an iodine solution. Initially, a blackish-blue color is formed, but during the break-down of the starch the blue color gets weaker and gradually turns into a reddish-brown, which is compared to a colored glass standard.
One Kilo Novo alpha amylase Unit (KNU) is defined as the amount of enzyme which, under standard conditions {i.e., at 37°C +/- 0.05; 0.0003 M Ca2+; and pH 5.6) dextrinizes 5260 mg starch dry substance Merck Amylum solubile.
A folder EB-SM-0009.02/01 describing this analytical method in more detail is available upon request to Novozymes A/S, Denmark, which folder is hereby included by reference.
Acid alpha-amylase activity (AFAU)
When used according to the present invention the activity of an acid alpha-amylase may be measured in FAU-F (Fungal Alpha-Amylase Unit) or AFAU (Acid Fungal Alpha-amylase Units).
Determination of FAU-F
FAU-F Fungal Alpha-Amylase Units (Fungamyl) is measured relative to an enzyme standard of a declared strength.
Figure imgf000046_0001
A folder (EB-SM-0216.02) describing this standard method in more detail is available on request from Novozymes A/S, Denmark, which folder is hereby included by reference.
Acid alpha-amylase activity (AFAU)
Acid alpha-amylase activity may be measured in AFAU (Acid Fungal Alpha-amylase Units), which are determined relative to an enzyme standard. 1 AFAU is defined as the amount of enzyme which degrades 5.260 mg starch dry matter per hour under the below mentioned standard conditions. Acid alpha-amylase, an endo-alpha-amylase (1 ,4-alpha-D-glucan-glucanohydrolase, E.C. 3.2.1.1 ) hydrolyzes alpha-1 ,4-glucosidic bonds in the inner regions of the starch molecule to form dextrins and oligosaccharides with different chain lengths. The intensity of color formed with iodine is directly proportional to the concentration of starch. Amylase activity is determined using reverse colorimetry as a reduction in the concentration of starch under the specified analytical conditions.
ALPHA - AMYLASE
STARCH + IODINE 40 : , pH 2,5 > DEXTRINS + OLIGOSACCHARIDES
λ = 590 nm
blue/violet t = 23 sec. decoloration
Standard conditions/reaction conditions:
Substrate: Soluble starch, approx. 0.17 g/L Buffer: Citrate, approx. 0.03 M
Iodine (I2): 0.03 g/L
CaCI2: 1.85 mM
pH: 2.50 ± 0.05
Incubation temperature: 40°C
Reaction time: 23 seconds
Wavelength: 590nm
Enzyme concentration: 0.025 AFAU/mL
Enzyme working range: 0.01 -0.04 AFAU/mL
A folder EB-SM-0259.02/01 describing this analytical method in more detail is available upon request to Novozymes A/S, Denmark, which folder is hereby included by reference.
Measurement of Cellulase Activity Using Filter Paper Assay (FPU assay)
1. Source of Method
1.1 The method is disclosed in a document entitled "Measurement of Cellulase Activities" by Adney and Baker, 1996, Laboratory Analytical Procedure, LAP-006, National Renewable Energy Laboratory (NREL). It is based on the lUPAC method for measuring cellulase activity (Ghose, 1987, Measurement of Cellulase Activities, Pure & Appl. C em. 59: 257-268. 2. Procedure
2.1 The method is carried out as described by Adney and Baker, 1996, supra, except for the use of a 96 well plates to read the absorbance values after color development, as described below.
2.2 Enzyme Assay Tubes:
2.2.1 A rolled filter paper strip (#1 Whatman; 1 X 6 cm; 50 mg) is added to the bottom of a test tube (13 X 100 mm).
2.2.2 To the tube is added 1.0 mL of 0.05 M Na-citrate buffer (pH 4.80).
2.2.3 The tubes containing filter paper and buffer are incubated 5 min. at 50°C (± 0.1 °C) in a circulating water bath.
2.2.4 Following incubation, 0.5 mL of enzyme dilution in citrate buffer is added to the tube.
Enzyme dilutions are designed to produce values slightly above and below the target value of 2.0 mg glucose.
2.2.5 The tube contents are mixed by gently vortexing for 3 seconds.
2.2.6 After vortexing, the tubes are incubated for 60 mins. at 50°C (± 0.1 °C) in a circulating water bath.
2.2.7 Immediately following the 60 min. incubation, the tubes are removed from the water bath, and 3.0 mL of DNS reagent is added to each tube to stop the reaction. The tubes are vortexed 3 seconds to mix.
2.3 Blank and Controls
2.3.1 A reagent blank is prepared by adding 1.5 mL of citrate buffer to a test tube.
2.3.2 A substrate control is prepared by placing a rolled filter paper strip into the bottom of a test tube, and adding 1 .5 mL of citrate buffer.
2.3.3 Enzyme controls are prepared for each enzyme dilution by mixing 1 .0 mL of citrate buffer with 0.5 mL of the appropriate enzyme dilution.
2.3.4 The reagent blank, substrate control, and enzyme controls are assayed in the same manner as the enzyme assay tubes, and done along with them.
2.4 Glucose Standards
2.4.1 A 100 mL stock solution of glucose (10.0 mg/mL) is prepared, and 5 mL aliquots are frozen. Prior to use, aliquots are thawed and vortexed to mix.
2.4.2 Dilutions of the stock solution are made in citrate buffer as follows:
G1 = 1.0 mL stock + 0.5 mL buffer = 6.7 mg/mL = 3.3 mg/0.5 mL
G2 = 0.75 mL stock + 0.75 mL buffer = 5.0 mg/mL = 2.5 mg/0.5 mL G3 = 0.5 ml. stock + 1.0 mL buffer = 3.3 mg/mL = 1 .7 mg/0.5 mL
G4 = 0.2 mL stock + 0.8 mL buffer = 2.0 mg/mL = 1 .0 mg/0.5 mL
2.4.3 Glucose standard tubes are prepared by adding 0.5 mL of each dilution to 1.0 mL of citrate buffer.
2.4.4 The glucose standard tubes are assayed in the same manner as the enzyme assay tubes, and done along with them.
2.5 Color Development
2.5.1 Following the 60 min. incubation and addition of DNS, the tubes are all boiled together for 5 mins. in a water bath.
2.5.2 After boiling, they are immediately cooled in an ice/water bath.
2.5.3 When cool, the tubes are briefly vortexed, and the pulp is allowed to settle. Then each tube is diluted by adding 50 microL from the tube to 200 microL of ddH20 in a 96-well plate. Each well is mixed, and the absorbance is read at 540 nm.
2.6 Calculations (examples are given in the NREL document)
2.6.1 A glucose standard curve is prepared by graphing glucose concentration (mg/0.5 mL) for the four standards (G1 -G4) vs. A540. This is fitted using a linear regression (Prism Software), and the equation for the line is used to determine the glucose produced for each of the enzyme assay tubes.
2.6.2 A plot of glucose produced (mg/0.5 mL) vs. total enzyme dilution is prepared, with the Y- axis (enzyme dilution) being on a log scale.
2.6.3 A line is drawn between the enzyme dilution that produced just above 2.0 mg glucose and the dilution that produced just below that. From this line, it is determined the enzyme dilution that would have produced exactly 2.0 mg of glucose.
2.6.4 The Filter Paper Units/mL (FPU/mL) are calculated as follows:
FPU/mL = 0.37/ enzyme dilution producing 2.0 mg glucose
Protease Assay method - AU(RH)
The proteolytic activity may be determined with denatured hemoglobin as substrate. In the Anson-Hemoglobin method for the determination of proteolytic activity denatured hemoglobin is digested, and the undigested hemoglobin is precipitated with trichloroacetic acid (TCA). The amount of TCA soluble product is determined with phenol reagent, which gives a blue color with tyrosine and tryptophan. One Anson Unit (AU-RH) is defined as the amount of enzyme which under standard conditions (i.e., 25°C, pH 5.5 and 10 min. reaction time) digests hemoglobin at an initial rate such that there is liberated per minute an amount of TCA soluble product which gives the same color with phenol reagent as one milliequivalent of tyrosine.
The AU(RH) method is described in EAL-SM-0350 and is available from Novozymes A S
Denmark on request.
Proteolytic Activity (AU)
The proteolytic activity may be determined with denatured hemoglobin as substrate. In the Anson-Hemoglobin method for the determination of proteolytic activity denatured hemoglobin is digested, and the undigested hemoglobin is precipitated with trichloroacetic acid (TCA). The amount of TCA soluble product is determined with phenol reagent, which gives a blue color with tyrosine and tryptophan.
One Anson Unit (AU) is defined as the amount of enzyme which under standard conditions (i.e., 25°C, pH 7.5 and 10 min. reaction time) digests hemoglobin at an initial rate such that there is liberated per minute an amount of TCA soluble product which gives the same color with phenol reagent as one milliequivalent of tyrosine.
A folder AF 4/5 describing the analytical method in more detail is available upon request to Novozymes A/S, Denmark, which folder is hereby included by reference.
Protease assay method (LAPU)
1 Leucine Amino Peptidase Unit (LAPU) is the amount of enzyme which decomposes 1 microM substrate per minute at the following conditions: 26 mM of L-leucine-p-nitroanilide as substrate, 0.1 M Tris buffer (pH 8.0), 37°C, 10 minute reaction time.
LAPU is described in EB-SM-0298.02/01 available from Novozymes A/S Denmark on request.
Determination of Maltogenic Amylase activity (MANU)
One MANU (Maltogenic Amylase Novo Unit) may be defined as the amount of enzyme required to release one micro mole of maltose per minute at a concentration of 10 mg of maltotriose (Sigma M 8378) substrate per ml of 0.1 M citrate buffer, pH 5.0 at 37°C for 30 minutes. EXAMPLES
Example 1
Effect of Using of Chondroitin sulphate in SSF
Trials to gauge the effectiveness of chondroitin sulphate during fermentation performed.
Industrial liquefied corn mash from Corn LP was used in SSF (=5g mash). The liquefied mash (« 35.7% DS (Dry Solids) was pH adjusted to 5.0 using 40% v/v H2S04. Urea and penicillin was added at 500 ppm and 3 ppm, respectively, prior to the mash being aliquoted into 15 ml conical centrifuge tubes. Enzymes and compounds were dosed using the equation below to calculate the dosage. Glucoamylase E was dosed at a rate of 0.6 AGU/g solids. Finally, H20 was added as a volume correction to make the ethanol concentration of each tube comparable. A target of =30 million cells/g mash of hydrated RED STAR™ yeast (Saccharomyces cerevisiae) was added to each tube before being incubated in a 32°C water bath for 54 hours. After a 54 hour fermentation time tubes were centrifuged and the liquid fraction was syringe filtered for HPLC analysis of ethanol and glucose.
_ . .. Fiaai eaz. dose( g g DS xMash e gh t fg) >;SoSd eoateat (%DS)
tin d -e (nil ; = ——— —t
(Cose, eszyme mg^st)
As shown in Fig. 1 the ethanol yield was increased when
10, 50 and 100 mg were added to 5 g mash (i.e., per tube).
A dose of 50 mg chondroitin sulphate/tube (i.e., 5 g mash) gave the highest ethanol yield improvement. Fig. 2 shows the glycerol level when adding 10, 50 and 100 mg chondroitin sulphate per tube. Fig. 3 shows the residual glucose levels for 10, 50 and 100 mg chondroitin sulphate per tube (i.e., 5 g mash). Increased levels of glucose in addition to higher ethanol titer indicate a more efficient fermentation is taking place.

Claims

1. A process of fermenting sugars derived from plant material into a fermentation product using a fermenting organism, wherein chondroitin sulphate is present or added before and/or during fermentation.
2. The process of claim 1 , wherein chondroitin sulphate is added in fermentation.
3. The process of any of claims 1-2, wherein chondroitin sulphate is added before fermentation, such as in a pre-saccharification step.
4. The process of any of claims 1-3, wherein the sugars derived from plant material are derived from starch-containing material or lignocellulose-containing material, or a mixture thereof.
5. The process of any of claims 1-4, wherein chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01-200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1-40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1 -25 mg/g mash, such as around 10 mg/g mash.
6. The process of any of claims 1 -5, wherein the fermentation product is an alcohol, preferably ethanol, especially fuel ethanol, potable ethanol and/or industrial ethanol.
7. The process of any of claims 1-6, wherein chondroitin sulphate boosts the fermentation yield compared to a corresponding fermentation where no chondroitin sulphate is present and/or added.
8. A process of producing a fermentation product from starch-containing material comprising the steps of:
i) liquefying starch-containing material using an alpha-amylase;
ii) saccharifying the liquefied material using a carbohydrate-source generating enzyme; iii) fermenting using a fermenting organism; wherein fermentation is carried out as defined in any of claims 1-7.
9. The process of claims 8 or 9, wherein the temperature during liquefaction is above the initial gelatinization temperature of starch
10. The process of producing a fermentation product from starch-containing material, comprising the steps of:
(a) saccharifying starch-containing material at a temperature below the initial gelatinization temperature of said starch-containing material,
(b) fermenting using a fermenting organism,
wherein fermentation is carried out as defined in any of claims 1 -7.
1 1 . The process of claim 10, wherein steps (a) and (b) are carried out simultaneously or sequentially.
12. The process of claim 10 or 1 1 , wherein the starch-containing material is granular starch.
13. A process of producing a fermentation product from lignocellulose-containing material, comprising the steps of:
(a) pre-treating lignocellulose-containing material;
(b) hydrolyzing the material;
(c) fermenting using a fermenting organism;
wherein fermentation is carried out as defined in any of claims 1 -7.
14. The process of claims 13, wherein chondroitin sulphate is present or dosed into fermentation in a concentration the range from 0.01-200 mg/g mash, preferably 0.02- 100 mg/g mash, such as 0.05-50 mg/g mash, such as 0.1-40 mg/g mash, preferably 0.5-30 mg/g mash, such as 1 -25 mg/g mash, such as around 10 mg/g mash.
15. A composition comprising chondroitin sulphate and one or more enzymes and/or one or more fermenting organisms.
16. The composition of claim 15, wherein the enzyme(s) is one or more hydrolases (class EC 3 according to Enzyme Nomenclature) selected from the group consisting of cellulases, hemicellulases, proteases, alpha-amylases, glucoamylases, or a mixture thereof.
17. Use of chondroitin sulphate for propagating fermenting organisms.
18. Use of chondroitin sulphate in a fermentation process.
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