WO2010032762A1 - セルロース加水分解力強化酵母の作製および使用 - Google Patents
セルロース加水分解力強化酵母の作製および使用 Download PDFInfo
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- WO2010032762A1 WO2010032762A1 PCT/JP2009/066193 JP2009066193W WO2010032762A1 WO 2010032762 A1 WO2010032762 A1 WO 2010032762A1 JP 2009066193 W JP2009066193 W JP 2009066193W WO 2010032762 A1 WO2010032762 A1 WO 2010032762A1
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P7/00—Preparation of oxygen-containing organic compounds
- C12P7/02—Preparation of oxygen-containing organic compounds containing a hydroxy group
- C12P7/04—Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
- C12P7/06—Ethanol, i.e. non-beverage
- C12P7/08—Ethanol, i.e. non-beverage produced as by-product or from waste or cellulosic material substrate
- C12P7/10—Ethanol, i.e. non-beverage produced as by-product or from waste or cellulosic material substrate substrate containing cellulosic material
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
- C12N9/14—Hydrolases (3)
- C12N9/24—Hydrolases (3) acting on glycosyl compounds (3.2)
- C12N9/2402—Hydrolases (3) acting on glycosyl compounds (3.2) hydrolysing O- and S- glycosyl compounds (3.2.1)
- C12N9/2405—Glucanases
- C12N9/2434—Glucanases acting on beta-1,4-glucosidic bonds
- C12N9/2437—Cellulases (3.2.1.4; 3.2.1.74; 3.2.1.91; 3.2.1.150)
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Y—ENZYMES
- C12Y302/00—Hydrolases acting on glycosyl compounds, i.e. glycosylases (3.2)
- C12Y302/01—Glycosidases, i.e. enzymes hydrolysing O- and S-glycosyl compounds (3.2.1)
- C12Y302/01004—Cellulase (3.2.1.4), i.e. endo-1,4-beta-glucanase
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Y—ENZYMES
- C12Y302/00—Hydrolases acting on glycosyl compounds, i.e. glycosylases (3.2)
- C12Y302/01—Glycosidases, i.e. enzymes hydrolysing O- and S-glycosyl compounds (3.2.1)
- C12Y302/01021—Beta-glucosidase (3.2.1.21)
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Y—ENZYMES
- C12Y302/00—Hydrolases acting on glycosyl compounds, i.e. glycosylases (3.2)
- C12Y302/01—Glycosidases, i.e. enzymes hydrolysing O- and S-glycosyl compounds (3.2.1)
- C12Y302/01091—Cellulose 1,4-beta-cellobiosidase (3.2.1.91)
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- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E50/00—Technologies for the production of fuel of non-fossil origin
- Y02E50/10—Biofuels, e.g. bio-diesel
Definitions
- the present invention relates to the production and use of a cellulose hydrolyzing power enhanced yeast.
- non-edible carbon source soft biomass eg, rice straw, wheat straw, bagasse, rice husk, cotton Ethanol production from wastes such as bamboo, paper, and corn stover.
- a method has been proposed in which a biomass containing cellulose or hemicellulose is subjected to an acid treatment or a supercritical treatment, and the raw material is treated to glucose that can be assimilated by fermentation microorganisms.
- an acid saccharification method and an enzymatic saccharification method as a method for producing glucose using a cellulose material as a raw material.
- acid saccharification methods there are known a dilute acid saccharification method using a dilute acid at a high temperature (200 ° C. or higher) and a saccharification method using concentrated sulfuric acid.
- the cellulose material is hydrolyzed under extreme conditions, so that a secondary decomposition reaction of glucose, which is a decomposition product of the cellulose material, occurs, and the saccharification rate is as low as about 50%. It is necessary to remove the degradation product of glucose.
- the enzymatic saccharification method can saccharify the cellulose material under mild conditions, but has a problem that the saccharification reaction rate is slow and sufficient saccharification takes a long time.
- the commercially available enzyme used for saccharification has a low titer, a large amount of enzyme is required for sufficient saccharification, which increases the cost of the enzyme used.
- a cell surface display technique is preferably used.
- yeast that surface-displays a group of enzymes that hydrolyze cellulose is produced by cell surface display technology (Patent Documents 1 and 2).
- Yeast Saccharomyces cerevisiae cannot metabolize xylose, but xylan-degrading enzyme Trichoderma reesei xylanase 2 (XYNII) and Aspergillus oryzae-derived ⁇ -xylosidase (XylA) is displayed on the surface and xylose reductase (XR) gene and xylitol dehydrogenase (XDH) gene (both derived from Pichia stipitis) and xylulokinase (XK) gene (derived from Saccharomyces cerevisiae) are expressed Saccharomyces cerevisiae has been produced, and an attempt has been made to produce ethanol from xylan as a cocoon using this yeast (Non-patent Document 1).
- XYNII Trichoderma reesei xylanase 2
- XylA Aspergillus oryzae-derived
- An object of the present invention is to provide a yeast having a high cellulose hydrolyzing power. Furthermore, this invention aims at providing the method of producing ethanol efficiently from a cellulosic substance.
- the present invention provides a method for producing a cellulose hydrolyzing power enhanced yeast.
- This method A process for obtaining a transformed yeast by introducing a gene group of an enzyme capable of hydrolyzing cellulose into cellulose non-hydrolyzable yeast, wherein the gene group comprises an enzyme gene and an amorphous substance capable of hydrolyzing crystalline cellulose.
- An enzyme gene capable of hydrolyzing crystalline cellulose, and an enzyme gene capable of hydrolyzing the crystalline cellulose and an enzyme gene capable of hydrolyzing the amorphous cellulose were introduced together with an increased number of incorporated copies. Including a process.
- the enzyme capable of hydrolyzing the crystalline cellulose is cellobiohydrolase, and the enzyme capable of hydrolyzing the amorphous cellulose is endoglucanase.
- the cellulose non-hydrolyzable yeast is introduced so that at least one of an enzyme capable of hydrolyzing the crystalline cellulose and an enzyme capable of hydrolyzing the amorphous cellulose is displayed on the surface. .
- the gene group of enzymes capable of hydrolyzing cellulose further comprises an enzyme gene capable of hydrolyzing cellobiose or cellooligosaccharide.
- the enzyme capable of hydrolyzing the crystalline cellulose and the enzyme capable of hydrolyzing the amorphous cellulose for one copy of the incorporated copy number of the gene of the enzyme capable of hydrolyzing the cellobiose or cellooligosaccharide The number of embedded copies of at least 2 copies.
- the enzyme capable of hydrolyzing cellobiose or cellooligosaccharide is ⁇ -glucosidase.
- the cellulose non-hydrolyzable yeast is introduced so that the enzyme capable of hydrolyzing cellobiose or cellooligosaccharide is displayed on the surface.
- the present invention further provides a yeast having enhanced cellulose hydrolyzing power, which is obtained by the above method.
- the present invention also includes a cellobiohydrolase gene, an endoglucanase gene, and a ⁇ -glucosidase gene, and each cellobiohydrolase gene and endoglucanase gene each have at least two copies relative to one copy of the ⁇ -glucosidase gene.
- a cellulose hydrolyzing power-enhanced yeast incorporated in (1) is provided.
- the cellobiohydrolase, endoglucanase, and ⁇ -glucosidase are displayed on the surface.
- the present invention provides a method for producing ethanol.
- This method A step of reacting the cellulosic material with the cellulose hydrolyzing power-enhanced yeast to produce ethanol is included.
- a yeast having enhanced cellulose hydrolyzing power is provided.
- This cellulose hydrolyzing power-enhanced yeast increases the ethanol production directly from cellulose. Furthermore, the use of this cellulose hydrolyzing power-enhanced yeast provides an efficient and economical method for producing ethanol from cellulosic materials.
- FIG. 6 is a schematic diagram of plasmid pRS406 EG CBH2.
- FIG. 6 is a schematic diagram of plasmid pRS403 EG CBH2.
- FIG. 6 is a schematic diagram of plasmid pRS405 EG CBH2.
- It is a schematic diagram of plasmid pILGP3-CBH2.
- FIG. 5 is a schematic diagram of plasmid pRS405HCBH2 CBH2.
- cellulose is hydrolyzed with respect to yeast (such as wild-type yeast) that has essentially no or almost no ability to hydrolyze cellulose (also referred to as “cellulose non-hydrolyzable yeast” in the present specification).
- yeast such as wild-type yeast
- cellulose non-hydrolyzable yeast By performing genetic recombination so as to express a group of enzymes that can be degraded, a transformed yeast having enhanced cellulose hydrolyzing power is produced.
- An enzyme capable of hydrolyzing cellulose can be derived from any cellulose hydrolase-producing bacterium.
- Cellulose hydrolase producing bacteria typically include the genus Aspergillus (for example, Aspergillus aculeatus, Aspergillus niger, and Aspergillus oryzae), Trichoderma (for example, Trichoderma reesei), Clostridium (eg, Clostridium thermocellum), Cellulomonas (eg, Cellulomonas fimi and Cellulomonas uda), Examples include microorganisms belonging to the genus Pseudomonas (for example, Pseudomonas fluorescence).
- the enzyme capable of hydrolyzing cellulose can be an enzyme capable of cleaving a ⁇ 1,4-glucoside bond.
- enzymes capable of cleaving a ⁇ 1,4-glucoside bond include endo ⁇ 1,4-glucanase (hereinafter simply referred to as “endoglucanase”), cellobiohydrolase, and ⁇ -glucosidase. It is not limited to.
- Endoglucanase is an enzyme usually referred to as cellulase, which cleaves cellulose from the inside of the molecule to produce glucose, cellobiose, and cellooligosaccharide (the degree of polymerization is 3 or more and usually 10 or less. (“Cellulose intramolecular cleavage”)). Endoglucanase is highly reactive to low crystallinity or amorphous cellulose, such as non-crystallized cellulose, soluble cellooligosaccharides, and cellulose derivatives such as carboxymethylcellulose (CMC), but has a crystalline structure Reactivity to cellulose microfibrils is low.
- CMC carboxymethylcellulose
- Endoglucanase is a representative example of an enzyme capable of hydrolyzing amorphous cellulose (hereinafter also referred to as “amorphous hydrolase”).
- amorphous hydrolase There are five types of endoglucanases, which are called endoglucanase I, endoglucanase II, endoglucanase III, endoglucanase IV, and endoglucanase V, respectively. These distinctions are differences in amino acid sequences, but are common in that they have a cellulose intramolecular cleavage action.
- endoglucanase derived from Trichoderma reesei can be used, but is not limited thereto.
- Cellobiohydrolase can be decomposed from either the reducing end or non-reducing end of cellulose to release cellobiose (“cellulose molecular end cleavage”).
- Cellobiohydrolase can degrade crystalline cellulose such as cellulose microfibrils having a crystalline structure, but is reactive to low crystallinity or amorphous cellulose such as cellulose derivatives such as carboxymethylcellulose (CMC). Is low.
- Cellobiohydrolase is a representative example of an enzyme capable of hydrolyzing crystalline cellulose (hereinafter also referred to as “crystalline hydrolase”).
- cellobiohydrolase 1 Hydrolysis of crystalline cellulose by cellobiohydrolase is slower than hydrolysis of amorphous cellulose by endoglucanase due to the strong structure of crystalline cellulose due to intermolecular and intramolecular close hydrogen bonds.
- Cellobiohydrolase 2 There are two types of cellobiohydrolase, which are called cellobiohydrolase 1 and cellobiohydrolase 2, respectively. These distinctions are differences in amino acid sequences, but are common in that they have a cellulose molecule end cleaving action. For example, but not limited to Trichoderma reesei cellobiohydrolase (particularly CBH2).
- ⁇ -glucosidase is an exo-type hydrolase that separates glucose units from non-reducing ends in cellulose.
- ⁇ -glucosidase can cleave ⁇ 1,4-glucoside bond between aglycone or sugar chain and ⁇ -D-glucose, and can hydrolyze cellobiose or cellooligosaccharide to produce glucose.
- ⁇ -glucosidase is a representative example of an enzyme capable of hydrolyzing cellobiose or cellooligosaccharide.
- One type of ⁇ -glucosidase is currently known and is referred to as ⁇ -glucosidase 1.
- Aspergillus acreatas-derived ⁇ -glucosidase can be used, but is not limited thereto.
- a transformed yeast can be prepared by introducing a gene group of enzymes capable of hydrolyzing cellulose.
- the gene group of enzymes capable of hydrolyzing cellulose includes genes of enzymes capable of hydrolyzing crystalline cellulose and genes of enzymes capable of hydrolyzing amorphous cellulose.
- An enzyme capable of hydrolyzing crystalline cellulose (“crystalline hydrolase”) refers to any enzyme capable of hydrolyzing cellulose having a crystal structure such as microfibril, and examples thereof include cellobiohydrolase. However, it is not limited to this.
- an enzyme capable of hydrolyzing amorphous cellulose does not degrade cellulose having a crystalline structure, but has a low crystallinity or non-crystallinity such as amorphous cellulose. It refers to any enzyme capable of hydrolyzing a natural cellulose chain, and examples thereof include, but are not limited to, endoglucanase.
- the gene group of enzymes capable of hydrolyzing cellulose may further include genes of enzymes capable of hydrolyzing cellobiose or cellooligosaccharide.
- the cellooligosaccharide is as described above. Examples of the enzyme capable of hydrolyzing cellobiose or cellooligosaccharide include, but are not limited to, ⁇ -glucosidase.
- a transformed yeast is produced. That is, the yeast is introduced into a non-hydrolyzable cellulose yeast with an incorporated copy number in which the gene copy number of each enzyme is increased together to obtain a transformed yeast.
- the expression pattern of the crystalline hydrolase and the amorphous hydrolase is not limited as long as the expressed enzyme acts on the cellulose substrate.
- the expression pattern can be surface presentation or secretory expression.
- At least one or both of the crystalline hydrolase and the amorphous hydrolase can be surface-presented or secreted.
- the yeast may be transformed so that surface presentation and secretion of crystalline and amorphous hydrolases occur simultaneously.
- an enzyme gene that can hydrolyze cellobiose or cellooligosaccharide is preferably incorporated. Thereby, the ability to produce glucose from cellulose can be enhanced.
- This enzyme can also be surface displayed or secreted, but is preferably surface displayed.
- an enzyme capable of hydrolyzing cellobiose or cellooligosaccharide is also expressed in yeast.
- the number of incorporated copies of the gene of the enzyme capable of hydrolyzing cellobiose or cellooligosaccharide is 1 copy, and the number of incorporated copies of each gene of the crystalline hydrolase and the amorphous hydrolase can be at least 2 copies.
- cellobiohydrolase can be used as a crystalline hydrolase
- endoglucanase can be used as an amorphous hydrolase.
- a single yeast can be transformed with at least two vectors that together contain the expression cassettes for the genes of these enzymes (detailed below).
- a single yeast may be transformed with at least two sets of combinations of vectors each containing an expression cassette for the gene of each of these enzymes.
- the practical yeast does not originally have an auxotrophic marker and it is desirable to impart an auxotrophic marker. It is preferable in terms of the efficiency of the operation to prepare a vector containing the above expression cassettes (examples of vectors include the vectors described in the following Examples).
- the transformed yeast may be one in which ⁇ -glucosidase is further incorporated as an enzyme capable of hydrolyzing cellobiose or cellooligosaccharide.
- the ethanol production can be increased by increasing the cellobiohydrolase and endoglucanase integration copy numbers relative to the ⁇ -glucosidase gene integration copy number. Accordingly, at least two copies of each of the cellobiohydrolase and endoglucanase genes can be incorporated with respect to one copy copy of the ⁇ -glucosidase gene. Each of the genes for cellobiohydrolase and endoglucanase can be integrated in 3 copies or more for 1 copy of the ⁇ -glucosidase gene. By performing such genetic recombination on cellulose non-hydrolyzable yeast (such as wild-type yeast), yeast with increased ethanol production can be obtained.
- cellulose non-hydrolyzable yeast such as wild-type yeast
- cellobiohydrolase and endoglucanase are surface displayed or secreted, and ⁇ -glucosidase is incorporated to be surface displayed.
- cellobiohydrolase, endoglucanase, and ⁇ -glucosidase can be displayed on the surface.
- the transformed yeast obtained as described above is given the ability to hydrolyze cellulose and becomes an enhanced yeast.
- a transformed yeast having the ability to hydrolyze cellulose and enhanced is also referred to as “cellulose hydrolyzing power enhanced yeast”.
- yeast having enhanced cellulose hydrolyzing power that is, production of transformed yeast
- the gene of the enzyme intended for expression can be obtained from a microorganism producing the enzyme by designing a primer or a probe based on known sequence information and using PCR or a hybridization method.
- An expression cassette can be constructed using an enzyme gene.
- the expression cassette may contain so-called regulatory elements such as operators, promoters, terminators, enhancers and the like that regulate the expression of the gene.
- the promoter or terminator may be that of the gene intended for expression itself, or may be derived from another gene.
- promoters and terminators such as GAPDH (glyceraldehyde 3′-phosphate dehydrogenase), PGK (phosphoglycerate kinase), GAP (glyceraldehyde 3′-phosphate) can be used.
- GAPDH glycosaccharide
- PGK phosphoglycerate kinase
- GAP glycose
- the selection of the terminator depends on the expression of the target enzyme gene and can be appropriately selected by those skilled in the art.
- the expression cassette can further contain necessary functional sequences depending on the purpose of expression of the gene.
- the expression cassette can also include a linker, if desired.
- cell surface engineering techniques can be used. For example, (a) a method of presenting the cell surface localized protein on the cell surface via the GPI anchor, (b) a method of presenting on the cell surface via the sugar chain binding protein domain of the cell surface localized protein, and (c ) There is a method of presenting on the cell surface via a periplasmic free protein (other receptor molecule or target receptor molecule), but is not limited thereto.
- a periplasmic free protein other receptor molecule or target receptor molecule
- Cell surface localized proteins that can be used include ⁇ - or a-agglutinin which is a sex aggregation protein of yeast (used as a GPI anchor), Flo1 protein (Flo1 protein has various amino acid lengths on the N-terminal side, Can be used as a GPI anchor: for example, Flo42, Flo102, Flo146, Flo318, Flo428, etc .;
- Non-patent document 2 Flo1326 represents a full-length Flo1 protein, Flo protein (having no GPI anchor function and aggregation Floshort or Flolong using non-patent document 3), invertase (not using GPI anchor) which is a periplasm localized protein, and the like.
- a gene encoding a protein localized on the cell surface by a GPI anchor encodes a secretory signal sequence, a cell surface localized protein (sugar chain binding protein domain), and a GPI anchor attachment recognition signal sequence in this order from the N-terminal side.
- a cell surface localized protein (glycan binding protein) expressed from this gene in the cell is guided to the outside of the cell membrane by a secretion signal, and the GPI anchor attachment recognition signal sequence is selectively cleaved at the C-terminal. It binds to the GPI anchor of the cell membrane via the portion and is fixed to the cell membrane. Thereafter, it is cut by the PI-PLC near the base of the GPI anchor, incorporated into the cell wall, fixed to the cell surface layer, and presented to the cell surface layer.
- the secretory signal sequence generally refers to an amino acid sequence containing many amino acids rich in hydrophobicity, which is bound to the N-terminus of a protein (secretory protein) secreted extracellularly (including periplasm), Normally, secreted proteins are removed when they are secreted from inside the cell through the cell membrane.
- Any secretory signal sequence can be used as long as it is a secretory signal sequence capable of leading the expression product to the cell membrane, regardless of its origin.
- a glucoamylase secretion signal sequence, a yeast ⁇ - or a-agglutinin signal sequence, a secretion signal sequence of the expression product itself, and the like are preferably used as the secretion signal sequence. If the activity of other proteins fused to the cell surface binding protein is not affected, a part or all of the secretory signal sequence and the pro sequence may remain at the N-terminus.
- GPI anchor refers to a glycolipid called ethanolamine phosphate-6 mannose ⁇ 1-2 mannose ⁇ 1-6 mannose ⁇ 1-4 glucosamine ⁇ 1-6 inositol phospholipid, called glycosylphosphatidylinositol (GPI).
- GPI-PLC refers to phosphatidylinositol-dependent phospholipase C.
- the GPI anchor adhesion recognition signal sequence is a sequence recognized when the GPI anchor binds to the cell surface localized protein, and is usually located at or near the C terminal of the cell surface localized protein.
- the GPI anchor attachment signal sequence for example, the sequence of the C-terminal part of yeast ⁇ -agglutinin is preferably used. Since the GPI anchor adhesion recognition signal sequence is included on the C-terminal side of the sequence of 320 amino acids from the C-terminus of ⁇ -agglutinin, the gene used in the above method encodes a sequence of 320 amino acids from the C-terminus. DNA sequences are particularly useful.
- a DNA encoding a secretory signal sequence-a structural gene encoding a cell surface localized protein-a sequence having a DNA sequence encoding a GPI anchor adhesion recognition signal, and a structural gene encoding this cell surface localized protein By substituting all or part of the sequence with a DNA sequence encoding the target enzyme, recombinant DNA for presenting the target enzyme on the cell surface via the GPI anchor can be obtained.
- the cell surface localized protein is ⁇ -agglutinin
- the enzyme presented on the cell surface by introducing such DNA into yeast and expressing it has its C-terminal side immobilized on the surface.
- the sugar chain binding protein domain has a plurality of sugar chains, and this sugar chain interacts with or entangles with sugar chains in the cell wall. It is possible to stay. Examples thereof include sugar chain binding sites such as lectins and lectin-like proteins.
- sugar chain binding sites such as lectins and lectin-like proteins.
- an aggregation functional domain of GPI anchor protein and an aggregation functional domain of FLO protein can be mentioned.
- the aggregation functional domain of the GPI anchor protein is a domain that is located on the N-terminal side of the GPI anchoring domain, has a plurality of sugar chains, and is considered to be involved in aggregation.
- the enzyme is presented on the cell surface layer by binding the sugar chain binding protein domain (or aggregation function domain) of the cell surface localized protein to the target enzyme.
- the enzyme is bound to the N-terminal side of the sugar chain binding protein domain (or aggregation functional domain) of the cell surface localized protein
- the enzyme is bound to the C-terminal side
- the same or different enzymes can be bound to both the N-terminal side and the C-terminal side.
- DNA encoding secretory signal sequence-gene encoding target enzyme-structural gene encoding sugar chain binding protein domain (or aggregation functional domain) of cell surface localized protein or ( 2) DNA encoding secretory signal sequence-structural gene encoding sugar chain binding protein domain (or aggregation functional domain) of cell surface localized protein-gene encoding target enzyme; or (3) secretory signal sequence Encoding DNA-First gene encoding target enzyme-Structural gene encoding sugar chain binding protein domain (or aggregation functional domain) of cell surface localized protein-Second gene encoding target enzyme (However, the first gene and the second gene may be the same or different.
- the aggregation functional domain since the GPI anchor is not involved in the cell surface presentation, only a part of the DNA sequence encoding the GPI anchor attachment recognition signal sequence may be present in the recombinant DNA. It does not have to exist.
- the aggregation functional domain since the length of the domain can be easily adjusted (for example, either Floshort or Flolong can be selected), the enzyme can be displayed on the cell surface with a more appropriate length, and This is very useful in that it can be bound on either the N-terminus or C-terminus of the enzyme.
- a method using a periplasm free protein (other receptor molecule or target receptor molecule) will be described.
- the target enzyme can be expressed on the cell surface as a fusion protein with a periplasm free protein.
- the periplasmic free protein include invertase (Suc2 protein).
- the target enzyme can be appropriately fused to the N-terminal or C-terminal depending on these periplasmic free proteins.
- a method for secreting an enzyme out of a cell and expressing it in yeast is well known to those skilled in the art.
- a recombinant DNA in which the structural gene of the target enzyme is linked to the DNA encoding the secretory signal sequence may be prepared and introduced into yeast.
- a recombinant gene linked to the target structural gene may be prepared and introduced into yeast without using the cell surface display technique or the secretion signal.
- Synthesis and binding of DNA containing various sequences can be performed by techniques that can be commonly used by those skilled in the art.
- the binding between the secretory signal sequence and the structural gene of the target enzyme can be performed using site-directed mutagenesis. By using this method, it is possible to cleave the secretory signal sequence accurately and to express the active enzyme.
- the enzyme gene or expression cassette can be inserted into a vector in the form of a plasmid.
- a shuttle vector of yeast and E. coli is preferable.
- the vector can include regulatory sequences as described above.
- a yeast selection marker for example, a drug resistance gene, an auxotrophic marker gene (for example, a gene encoding imidazoleglycerol phosphate dehydrogenase (HIS3), a gene encoding malate beta-isopropyl dehydrogenase (LEU2), a gene encoding tryptophan synthase (TRP5), a gene encoding argininosuccinate lyase (ARG4), N- (5′-phosphoribosyl) anthranilate isomerase (TRP1) gene, histidinol dehydrogenase (HIS4) gene, orotidine-5-phosphate decarboxylase (URA3) Genes, genes encoding dihydroorotate dehydrogenase (URA1), genes encoding dihydroorotate dehydrogenase (URA1), genes encoding dihydroorotate dehydrogenase (URA1), genes encoding dihydro
- introduction of a gene or DNA means not only the introduction of a gene or DNA into a cell but also expression.
- gene or DNA introduction include transformation, transduction, transfection, co-transfection, and electroporation.
- specific examples of the introduction into yeast cells include a method using lithium acetate and a protoplast method.
- the introduced DNA may be present in the form of a plasmid, or may be inserted into a chromosome by being inserted into a host gene or undergoing homologous recombination with a host gene.
- the host yeast is a cellulose non-hydrolyzable yeast, which can be a wild type yeast.
- the type of yeast is not particularly limited, but yeast belonging to the genus Saccharomyces is particularly preferable, and Saccharomyces cerevisiae is preferable.
- it is a wild type yeast of a practical yeast. Wild-type yeast may be genetically modified to enhance the ability to ferment alcohol from a monosaccharide (eg, glucose) as a substrate.
- a monosaccharide eg, glucose
- “Practical yeast” refers to any yeast conventionally used in ethanol fermentation (for example, sake yeast, shochu yeast, wine yeast, brewer's yeast, baker's yeast, etc.).
- sake yeast having high ethanol fermentation ability and high ethanol tolerance and genetically stable is preferable.
- the “practical yeast” is a yeast having high ethanol tolerance, and is preferably a yeast that can survive even at an ethanol concentration of 10% or more. Further, it preferably has acid resistance, heat resistance and the like. More preferably, it may be cohesive.
- Saccharomyces cerevisiae NBRC1440 strain MAT ⁇ , haploid yeast, heat and acid resistant, and cohesive
- NBRC 1445 strain MATa, haploid yeast, heat and acid resistant, no cohesiveness).
- yeasts Since practical yeasts have extremely high resistance to ethanol, they can be used for ethanol fermentation as they are after producing monosaccharides. Among them, since it is resistant to various culture stresses, it is preferable in terms of showing stable cell growth even in industrial production in which strict control is difficult and harsh culture conditions may occur. In addition, since practical yeasts are polyploid, it is possible to incorporate multiple gene constructs (expression vectors) into homologous chromosomes, and as a result, compared to the case of integrating into laboratory yeasts, which are often haploid, Increases the expression level of the target protein.
- auxotrophic marker suitable for introducing the gene of interest is used as a practical yeast (particularly a yeast that does not have auxotrophy and has high ethanol resistance (preferably, even at an ethanol concentration of 10% or more).
- the auxotrophic marker includes, but is not limited to, uracil requirement, trypsin requirement, leucine requirement, histidine requirement, etc. due to its genetic manipulation.
- the uracil requirement can be imparted by transferring a ura3 - fragment obtained from a uracil requirement mutant (for example, Saccharomyces cerevisiae MT-8 strain) to a normal ura3 gene of a practical yeast.
- auxotrophy for example, trypsin requirement, leucine requirement, histidine requirement, etc.
- fragments are used to destroy these genes. Can be designed and granted.
- the practical yeast into which the expression cassette is incorporated and the gene for expression is introduced can be selected with a yeast selection marker (for example, the above-mentioned auxotrophic marker) as described above. Furthermore, it can be confirmed by measuring the activity of the expressed protein. Whether the protein is immobilized on the cell surface layer can be confirmed, for example, by an immunoantibody method using an anti-protein antibody and a FITC-labeled anti-IgG antibody.
- the cellulose hydrolyzing power-enhanced yeast as described above can be suitably used for ethanol production.
- the cellulose hydrolyzing power enhanced yeast can be reacted with a cellulose substrate (eg, a cellulosic material as described below).
- cellulosic material refers to any material, product, and composition containing cellulose.
- cellulose refers to a fibrous polymer in which glucopyranose is linked by ⁇ 1,4-glucoside bonds, but also includes derivatives or salts thereof, or those whose degree of polymerization has been reduced by decomposition.
- Cellulosic material includes, for example, paper products produced in the manufacture or recycling of paper, cotton products such as used clothing and waste towels, and wood parts or herbs of wood that are not harvested agriculturally or disposed of in the process of food production Also included are any materials containing cellulose, such as the foliage and skin (especially non-edible parts) of sex plants. “Cellulosic materials” can also include cellulose compounds such as carboxymethylcellulose (CMC) in which the cellulose is carboxymethylated, phosphate-swelled cellulose, and crystalline cellulose (eg, Avicel). Among cellulose compounds, phosphate-swelled cellulose is a cellulose that is often used as an alternative substrate for cellulose in actual biomass in order to measure the cellulose hydrolyzing power of an enzyme capable of hydrolyzing cellulose.
- CMC carboxymethylcellulose
- phosphate-swelled cellulose is a cellulose that is often used as an alternative substrate for cellulose in actual biomass in order to measure the cellulose hydrolyzing power of an
- the material containing cellulose exemplified above may contain a plant cell wall component mainly composed of cellulose.
- the plant cell wall usually contains hemicellulose and lignin as components in addition to cellulose.
- the content of these components may vary, but as long as cellulose is included, any species can grow to the extent of growth. It can be used regardless.
- cellulosic materials also include any materials and wastes and products that contain the plant cell wall components described above.
- Insoluble dietary fiber is also included in the “plant cell wall component content”.
- woody parts and the foliage and skin parts of herbaceous plants those processed from these parts (for example, corn fiber) are also included. This is preferable.
- Cellulosic substances include cellulose compounds themselves and compositions containing cellulose compounds, agricultural waste such as rice husks, bamboo, bagasse, straw, corn cobs, wood (wood chips, waste wood), old newspapers, magazines , Cardboard, office waste paper, linter, cotton, pulp and waste pulp discharged from paper manufacturers.
- agricultural waste such as rice husks, bamboo, bagasse, straw, corn cobs, wood (wood chips, waste wood), old newspapers, magazines , Cardboard, office waste paper, linter, cotton, pulp and waste pulp discharged from paper manufacturers.
- Cellulase enzyme includes any form isolated as an enzyme.
- “cellulase enzyme” includes an enzyme isolated and purified from a microorganism producing cellulase (ie, endoglucanase) as described above, and an enzyme produced by genetic recombination using a cellulase gene. It is done. Commercially available cellulase enzymes can also be used.
- cellulase enzymes examples include, for example, Cellulase® SS from Genencor, cellulase derived from Trichoderma reesei: titer 7.6 FPU / mL (“FPU” is an abbreviation for “Filter Paper Unit”, and 1 ⁇ mol glucose per minute from the filter paper. The amount of the enzyme that produces a reducing sugar corresponding to is assumed to be “1FPU”).
- a cellulase enzyme may be further added during the reaction with the cellulosic material in order to promote production efficiency.
- hemicellulose-degradable xylose-assimilating yeast may be further added.
- This yeast can be produced as follows. Xylose is obtained by enzymatic degradation from hemicellulose contained in a plant cell wall component containing cellulose as one of the main components.
- xylose derived from hemicellulose is also ethanol-fermented by separately producing a yeast (preferably a practical yeast) that expresses a gene encoding a xylose utilization gene and / or a xylan-degrading enzyme.
- yeast preferably a practical yeast
- an enzyme that degrades hemicellulose for example, xylan-degrading enzyme
- Examples of the xylan-degrading enzyme include xylanase (especially XYLII derived from Trichoderma reesei) and ⁇ -xylosidase (XylA derived from Aspergillus oryzae).
- Examples of xylose-assimilating genes include xylose metabolism enzymes such as xylose reductase (XR) gene and xylitol dehydrogenase (XDH) gene (both derived from Pichia stipitis) and xylulokinase (XK) gene ( Saccharomyces cerevisiae).
- xylanases especially XYLII (INSD accession number X69574; S51975) from Trichoderma reesei) and ⁇ -xylosidase (Aspergillus) to produce practical yeasts having both xylan degradation (hemicellulose degradation) and xylose utilization XylA derived from oryzae (INSD accession number AB013851)
- xylose-utilizing genes particularly xylose reductase (XR) gene XYL1 (INSD accession number X59465) derived from Pichia stipitis) XYL2 (INSD accession number X55392) which is a xylitol dehydrogenase (XDH) gene derived from Stipitis, and a xylem derived from Saccharomyces cerevisiae Be recombinantly prepared to express Rokinaze (XK) is a gene
- Non-Patent Document 1 The construction and transformation of an expression vector are described in Non-Patent Document 1 and Non-Patent Documents 5-7.
- Yeast obtained by this recombinant preparation is also referred to as hemicellulose-degradable xylose-utilizing yeast.
- the recombinant preparation of transformed yeast can also be carried out as described above.
- the above reaction step can be usually performed under conditions for ethanol fermentation.
- This reaction step is also referred to as a fermentation step in the present specification.
- the fermentation process can be performed by culturing yeast in a medium containing a cellulosic material.
- a fermentation process may be normally performed on the conditions which perform ethanol fermentation.
- the fermentation medium may further include components necessary or desirable for yeast growth. Examples of the fermentation process include a batch process, a fed-batch process, a repeated batch process, and a continuous process, and any of these may be used.
- the temperature during fermentation can usually be about 30-35 ° C.
- the fermentation pH is preferably about 4 to about 6, more preferably about 5.
- Fermentation culture can be performed anaerobically (dissolved oxygen concentration can be, for example, about 1 ppm or less, more preferably about 0.1 ppm or less, and even more preferably about 0.05 ppm or less).
- Factors such as the yeast load, the cellulosic load, and the fermentation time can be appropriately determined depending on requirements such as the fermentation reaction capacity and the target production amount of ethanol.
- the cellulosic material may be subjected to pressurized hot water treatment before being subjected to the fermentation process.
- pressurized hot water treatment include a non-catalytic hydrothermal method as described in Patent Document 1.
- a non-catalytic hydrothermal method for example, a cellulose unit or oligosaccharide having an appropriate length is formed, or a cross-link between fibers (for example, between cellulose) is removed, so that a cellulolytic enzyme can easily act. , May be processed.
- the raw material cellulose fiber having a concentration of about 10% by mass is 120 to 300 ° C, preferably 150 to 280 ° C. More preferably, the treatment can be carried out at 180 to 250 ° C., and the treatment time is generally preferably in the range of 1 hour to 15 seconds.
- the temperature can be raised slightly in relation to the heat history time, and the raw material cellulose fiber having a concentration of about 10% by mass is treated at 120 to 373 ° C., preferably 150 to 320 ° C., preferably 1 hour to 1 second. Can do.
- the pressurization can be automatically or manually set by a device such that a temperature within the above range can be achieved.
- Non-glycated parts such as lignin can be removed in advance from the woody part of wood and the foliage and skin parts (biomass) of herbaceous plants.
- a pressurized hot water treatment can be used to remove lignin.
- the pressurized hot water treatment is preferable because lignin can be removed without using a chemical such as acid or alkali.
- the method described in Patent Document 1 can be used.
- lignin can be separated by treating biomass with hot water at normal pressure or higher and 5 MPa or lower and 180 ° C. or higher and 374 ° C. or lower and then cooling to 100 ° C. or higher and 180 ° C. or lower.
- the cellulosic material Before being subjected to the fermentation process, for example, according to the method described in Patent Document 1, the cellulosic material can be treated with pressurized hot water. This removes lignin (if present) and the cellulose can be treated to facilitate the action of enzymes that can hydrolyze the cellulose.
- the ethanol-containing medium is withdrawn from the fermenter, and ethanol is isolated by a separation process commonly used by those skilled in the art, such as a separation operation using a centrifuge and a distillation operation.
- Cellulose hydrolyzing power-enhanced yeast (if necessary and hemicellulose-degradable xylose-assimilating yeast and cellulase enzyme) is preferably immobilized on a carrier. As a result, reuse becomes possible.
- the carrier and method to be immobilized are those commonly used by those skilled in the art, and examples thereof include a carrier binding method, a comprehensive method, and a crosslinking method.
- a porous body is preferably used as the carrier.
- foams or resins such as polyvinyl alcohol, polyurethane foam, polystyrene foam, polyacrylamide, polyvinyl formal resin porous body, and silicon foam are preferable.
- the size of the opening of the porous body can be determined in consideration of the microorganism to be used and its size, but in the case of a practical yeast, it is preferably 50 to 1000 ⁇ m.
- the shape of the carrier does not matter. Considering the strength of the carrier, the culture efficiency, etc., a spherical shape or a cubic shape is preferable.
- the size may be determined depending on the microorganism to be used. In general, the diameter is preferably 2 to 50 mm for a spherical shape, and 2 to 50 mm square for a cubic shape.
- the number of yeasts can be increased by culturing them under aerobic conditions before being subjected to fermentation.
- the medium may be a selective medium or a non-selective medium.
- the pH of the medium during culture is preferably about 4 to about 6, more preferably about 5.
- the dissolved oxygen concentration in the medium during aerobic culture is preferably about 0.5 to about 6 ppm, more preferably about 1 to about 4 ppm, and still more preferably about 2 ppm.
- the temperature during culture can be about 20 to about 45 ° C, preferably about 25 to about 35 ° C, more preferably about 30 ° C.
- the total yeast cell concentration is 20 g (wet amount) / L or more, more preferably 50 g (wet amount) / L, and even more preferably 75 g (wet amount) / L or more. About 20 to about 50 hours.
- a commercially available enzyme used for saccharification has a low titer, so that a sufficient amount of enzyme is required for sufficient saccharification, which increases the cost of the enzyme used.
- yeast with enhanced cellulose hydrolyzing power it is possible to reduce the amount of cellulase enzyme required to achieve a suitable ethanol production rate or rate, particularly in industrial production.
- ethanol production can be increased by using hemicellulose-degradable xylose-assimilating yeast.
- strains Saccharomyces cerevisiae NBRC1440 (MAT ⁇ ) and Saccharomyces cerevisiae MT8-1 (MATa ade his3 leu2 trp1 ura3) used in this example were obtained from the National Institute of Technology and Evaluation.
- yeast transformations shown in this example were performed with lithium acetate using a YEAST® MAKER yeast transformation system (Clontech® Laboratories, “Palo Alto, California, USA”).
- the 5-fluoroorotic acid (FOA) medium was prepared as follows. Uracil dropout synthetic dextrose (SD) medium (Non-patent Document 8) supplemented with 50 mg / L uracilic acid and 2% (w / v) agar was autoclaved and maintained at 65 ° C. FOA was dissolved in dimethyl sulfoxide (DMSO) at a concentration of 100 mg / mL and added to the autoclaved medium at about 65 ° C. to make the final concentration of FOA 1 mg / mL.
- DMSO dimethyl sulfoxide
- URA3 was amplified using pRS406 plasmid (Stratagene) as a template; The fusion fragment was amplified by mixing the products from PCR1 and PCR2 as templates using PCR3, HIS3-Green U (SEQ ID NO: 3; Forward) and HIS3-40Uc (SEQ ID NO: 6; Reverse) primers.
- NBRC1440 strain with URA3 marker prepared as described above was transformed by homologous recombination using the obtained fusion fragment. Strains without uracil requirement were selected on uracil dropout (uracil-free medium) plates. When this construct is integrated into the chromosome of the above-mentioned practical yeast NBRC1440, HIS3 gene disruption occurs, and the URA3 marker and the repeated sequences on both sides thereof are integrated into the chromosome.
- this transformant was grown in YPD medium at 30 ° C. for 24 hours. They were then grown to 1.0 ⁇ 10 7 cells / 200 ⁇ L on 5-FOA media plates. All colonies that grew on 5-FOA media plates were of the uracil auxotrophic (Ura ⁇ ) phenotype and were selected. In the transformant grown on the 5-FOA medium plate, because of the homologous recombination caused by the repetitive sequence on both sides of the URA3 marker, the URA3 marker that should have been introduced by transformation is removed from the chromosome, and uracil nutrition The phenotype of requirement (Ura ⁇ ) was shown.
- PCR1, TRP1-988 (SEQ ID NO: 7; Forward) and RP1-28r (SEQ ID NO: 8; Reverse) primers were used to amplify the TRP1 upstream partial sequence using the chromosomal DNA of Saccharomyces cerevisiae NBRC1440 as a template; URA3 was amplified using PCR2, TRP1-URA3 (SEQ ID NO: 9; Forward) and TRP1-40r (SEQ ID NO: 10; Reverse) primers, using pRS406 plasmid (Stratagene) as a template; The fusion fragment was amplified by mixing the products from PCR1 and PCR2 as templates using PCR3, TRP1-988 (SEQ ID NO: 7; Forward) and TRP1-40r (SEQ ID NO: 10; Reverse) primers.
- the NBRC1440 strain provided with the HIS3 and URA3 markers prepared as described above was transformed in the same manner as in Preparation Example 1-2, and finally, the URA3, HIS3, and TRP1 markers NBRC1440 strain to which
- the NBRC1440 strain provided with the URA3, HIS3, and TRP1, and LEU2 markers prepared as described above was transformed in the same manner as in Preparation Example 1-2, and finally, URA3 NBRC1440 strains with HIS3, TRP1, and LEU2 markers were obtained.
- This strain is represented as “NBRC1440 / UHWL” for convenience.
- PEG23u31H6 (non-patented) using as a template a 2719 bp DNA fragment encoding the secretory signal sequence of Rhizopus oryzae-derived glucoamylase gene and the 3 ′ half region of EGII gene and ⁇ -agglutinin gene (Non-patent document 9) Prepared by PCR using the primer pair of SEQ ID NO: 15 (Forward) and SEQ ID NO: 16 (Reverse).
- the PGK promoter was digested with XhoI and NheI, the multicloning site was digested with NheI and BglII, the PGK terminator was digested with BglII and NotI, respectively, and cloned into the XhoI-NotI site of the pTA2 vector (TOYOBO, Osaka, Japan).
- the obtained vector was digested with XhoI and NotI, the fragment was cloned into pRS406 (Stratagene), and the resulting vector was designated as pGK406.
- the above 2719 bp DNA fragment is digested with NheI and XmaI, inserted between the NheI and XmaI sites of plasmid pGK406 containing the URA3 gene and its promoter and terminator, PGK promoter and PGK terminator, and the URA3 gene and its promoter and terminator,
- a plasmid containing the PGK promoter, the secretory signal sequence of the Rhizopus oryzae-derived glucoamylase gene, the endoglucanase (EGII) gene, the 3 ′ half region of the ⁇ -agglutinin gene, and a PGK terminator was obtained.
- the obtained plasmid was designated as pGK406 EG.
- Non-patent Document 11 Using plasmid pFCBH2w3 (Non-patent Document 11) as a template, GAPDH (glyceraldehyde triphosphate dehydrogenase) promoter, secretion signal sequence of Rhizopus oryzae-derived glucoamylase gene, CBH2 gene from Trichoderma reesei, 3 ′ of ⁇ -agglutinin gene A fragment containing the side half region and the GAPDH terminator was amplified by PCR with a primer pair (SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse). The resulting fragment was digested with NotI and cloned into pGK406 EG digested with NotI.
- the obtained plasmid was designated as pRS406 EG CBH2, and a schematic diagram thereof is shown in FIG.
- UAA3 is a uracil gene marker
- GAPDH is a glyceraldehyde-3-phosphate dehydrogenase promoter
- PGK is a phosphoglycerate kinase promoter
- ss is a Rhizopus oryzae-derived glucoamylase gene.
- AG is the 3 ′ half region of ⁇ -agglutinin gene
- EG is EGII gene derived from Trichoderma reesei
- CBH2 is cellobiohydrolase 2 gene derived from Trichoderma reesei
- tGAP Represents glyceraldehyde-3-phosphate dehydrogenase terminator
- tPGK represents phosphoglycerate kinase terminator.
- a fragment containing PGK promoter, lysopus oryzae-derived glucoamylase gene secretion signal sequence, EGII gene, and PGK terminator was excised from pGK406 with ApaI and NotI, and pRS403 (Stratagene) was similarly digested with ApaI and NotI. The fragment was cloned. The obtained plasmid was designated as pGK403 EG.
- GAPDH glycosyl transfer protein
- secretion signal sequence of lysopus oryzae-derived glucoamylase gene
- CBH2 gene from Trichoderma reesei 3 ′ half region of ⁇ -agglutinin gene
- a fragment containing the GAPDH terminator was amplified by PCR with primers (SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse).
- SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse The resulting fragment was digested with NotI and cloned into NotI digested pGK403 EG.
- the obtained plasmid was designated as pRS403 EG CBH2, and a schematic diagram thereof is shown in FIG. In FIG. 2, “HIS3” represents a histidine gene marker, and other notations are the same as in FIG.
- pGK405 EG From pGK406, a fragment containing the PGK promoter, the secretory signal sequence of the Rhizopus oryzae-derived glucoamylase gene, EGII gene, and PGK terminator was excised with ApaI and NotI, and cloned into pRS405 (Stratagene) that was also digested with ApaI and NotI . The obtained plasmid was designated as pGK405 EG.
- GAPDH glycosyl transfer protein
- secretion signal sequence of lysopus oryzae-derived glucoamylase gene
- CBH2 gene from Trichoderma reesei 3 ′ half region of ⁇ -agglutinin gene
- a fragment containing the GAPDH terminator was amplified by PCR with primers (SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse).
- SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse The resulting fragment was digested with NotI and cloned into NotI digested pGK405 EG.
- the obtained plasmid was designated as pRS405 EG CBH2, and a schematic diagram thereof is shown in FIG. In FIG. 3, “LEU2” represents a leucine gene marker, and the other notations are the same as in FIG.
- a 2816 bp DNA fragment derived from plasmid pFCBH2w3 prepared as described in Preparation Examples 2 to 4 above was digested with XmaI and XbaI and inserted between the XmaI and XbaI sites of plasmid pILGP3 containing the GAPDH promoter and GAPDH terminator, LEU2 gene and promoter and terminator thereof, GAPDH promoter, secretion signal sequence of glucoamylase gene derived from Rhizopus oryzae, cellobiohydrolase (CBH2) gene derived from Trichoderma reesei, 3 ′ half region of ⁇ -agglutinin gene, and GAPDH terminator
- a plasmid containing was obtained.
- the resulting plasmid was named pILGP3-CBH2, and a schematic diagram thereof is shown in FIG. In FIG. 4, “LEU2” represents a leucine gene marker, and the other notations are the same as in FIG.
- This DNA fragment was digested with NcoI and XhoI, and the cell surface expression plasmid pIHCS (non-patent document 9) containing the secretory signal sequence of the Rhizopus oryzae-derived glucoamylase gene and the 3 ′ half region of the ⁇ -agglutinin gene (non-patent document 9) It was inserted into the NcoI-XhoI site of Patent Document 10). The resulting plasmid was named pIBG13.
- PCR was performed using a primer pair (SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse), and the GAPDH promoter, Rhizopus oryzae-derived glucoamylase secretion signal sequence, BGL1 gene, ⁇ -agglutinin gene 3
- SEQ ID NO: 23 Forward and SEQ ID NO: 24; Reverse
- GAPDH promoter Rhizopus oryzae-derived glucoamylase secretion signal sequence
- BGL1 gene ⁇ -agglutinin gene 3
- This fragment was digested with NotI and cloned into NotI digested pRS 404.
- the obtained plasmid was designated as pIWBGL, and a schematic diagram thereof is shown in FIG. In FIG.
- TRP1 represents a tryptophan gene marker
- GAPDH represents a glyceraldehyde-3-phosphate dehydrogenase promoter
- ss represents a secretory signal sequence of a Rhizopus oryzae-derived glucoamylase gene
- AG represents , The 3 ′ half region of the ⁇ -agglutinin gene
- BGL represents the ⁇ -glucosidase 1 (BGL1) gene derived from Aspergillus acreatas.
- Preparation Example 8 Preparation of yeast strain incorporating endoglucanase II having a copy number of 1
- NBRC1440 / UHWL was transformed with the linearized pGK406 EG cut with the restriction enzyme NdeI, and a strain having no uracil requirement was selected on a uracil dropout (uracil-free medium) plate.
- NBRC1440 / UHWL disrupted URA3 gene was restored by transformation with pGK406 EG, confirming gene introduction.
- This strain was named “NBRC1440 / pGK406 EG”.
- a surface-presenting strain of endoglucanase II having a copy number of 1 was prepared.
- Preparation Example 9 Preparation of yeast strain in which both endoglucanase II and cellobiohydrolase 2 were incorporated at a copy number of 1
- NBRC1440 / UHWL was transformed with the linearized pRS406 EG CBH2 cut with the restriction enzyme NdeI, and a strain having no uracil requirement was selected on a uracil dropout (uracil-free medium) plate.
- NBRC1440 / UHWL disrupted URA3 gene was restored by transformation with pRS406 EG CBH2, confirming gene transfer.
- This strain is named “NBRC1440 / pRS406 EG CBH2” and is also abbreviated as “NBRC1440 / EG-CBH2-1c”.
- a surface-displaying strain of endoglucanase II and cellobiohydrolase 2 having a copy number of 1 was prepared.
- Preparation Example 10 Preparation of a yeast strain into which endoglucanase II and cellobiohydrolase 2 were incorporated at a copy number of 2
- NBRC1440 / pRS406 EG CBH2 was transformed with the linearized pRS403 EG CBH2 cut with the restriction enzyme NdeI, and a strain having no histidine requirement was selected on a histidine dropout (histidine-free medium) plate.
- the transformation of pRS403 EG CBH2 restored the disrupted HIS3 gene of NBRC1440 / pRS406 EG CBH2, thereby confirming gene introduction.
- This strain is named “NBRC1440 / pRS406 EG CBH2 / pRS403 EG CBH2” and is also abbreviated as “NBRC1440 / EG-CBH2-2c”.
- surface-displaying strains of endoglucanase II and cellobiohydrolase 2 having a copy number of 2 were prepared.
- This strain is named “NBRC1440 / pRS406 EG CBH2 / pRS403 EG CBH2 / pRS405 EG CBH2”, and is also abbreviated as “NBRC1440 / EG-CBH2-3c”.
- surface display strains of endoglucanase II and cellobiohydrolase 2 having a copy number of 3 were prepared.
- NBRC1440 / pRS406 EG CBH2 was transformed with the linearized pILGP3-CBH2 cut with the restriction enzyme HpaI, and a strain having no leucine requirement was selected on a leucine dropout (leucine-free medium) plate.
- the transformation of pILGP3-CBH2 restored the disrupted LEU2 gene of NBRC1440 / EG-CBH2-1c, confirming gene introduction.
- This strain is named “NBRC1440 / pRS406 EG CBH2 / pILGP3-CBH2” and is also abbreviated as “NBRC1440 / EG-CBH2-1c-CBH2”.
- surface-presenting strains of endoglucanase II having a copy number of 1 and cellobiohydrolase 2 having a copy number of 2 were prepared.
- NBRC1440 / pRS406 EG CBH2 was transformed with the linearized pRS405 CBH2 CBH2 cut with the restriction enzyme HpaI, and a strain not requiring leucine was selected on a leucine dropout (leucine-free medium) plate.
- pRS405 CBH2 Transformation with CBH2 restored the disrupted LEU2 gene of NBRC1440 / EG-CBH2-1c, confirming gene introduction.
- This strain is named “NBRC1440 / pRS406 EG CBH2 / pRS405 CBH2 CBH2” and is also abbreviated as “NBRC1440 / EG-CBH2-1c-CBH2 ⁇ 2”.
- surface-displaying strains of endoglucanase II having a copy number of 1 and cellobiohydrolase 2 having a copy number of 3 were prepared.
- Example 1 Evaluation of cellulose hydrolyzing power
- PSC phosphoric acid swollen cellulose
- FIG. 7 is a graph showing the cellulose hydrolyzing power of yeast that variously expresses endoglucanase and cellobiohydrolase.
- the vertical axis represents enzyme activity (mU / g cell) per gram of yeast cells.
- NBRC1440 (“1440" in the figure), NBRC1440 / pGK406 EG (“EG” in the figure;
- Preparation Example 8 yeast strain incorporating endoglucanase II having a copy number of 1), NBRC1440 / EG-CBH2-1c (“EG CBH2” in the figure;
- Preparation Example 9 Yeast strain in which both endoglucanase II and cellobiohydrolase 2 were incorporated at a copy number of 1), NBRC1440 / EG-CBH2-1c-CBH2 (“CBH2” of “EG CBH2” in the figure;
- Preparation Example 12 Endoglucanase II and cellobiohydrolase 2 are both incorporated at a copy number of 1, and further a cellobiohydrolase of copy number 1) Yeast strain incorporating 2), NBRC1440 / EG-CBH2-1c-CBH
- Example 2 Ethanol fermentation test
- the PSC degradation activity increased each time the copy number was increased with the combination of “EG CBH2”. Therefore, in this example, ethanol fermentation from PSC was performed using strains into which two copies of the two cassettes of “EG CBH2” (two gene cassettes of EG and CBH2) were incorporated. It was.
- each of these three strains (NBRC1440 / EG-CBH2-1c, NBRC1440 / EG-CBH2-2c, NBRC1440 / EG-CBH2-3c) was added to pIWBGL ( ⁇ - A strain into which a glucosidase surface display expression vector) was incorporated was used. That is, three types of cellulase surface-displaying yeasts “NBRC1440 / EG-CBH2-1c / BGL”, “NBRC1440 / EG-CBH2-2c / BGL”, and “NBRC1440 / EG-CBH2-3c / BGL” were used.
- Yeast, SD medium supplemented with essential amino acids synthetic dextrose medium: yeast nitrogen source other than 6.7 g / L amino acids (Yeast nitro base without amino acids) [Difco) and appropriate supplements; 20 g / L Of glucose is added as a single carbon source) for 24 hours at a pH of about 5.0 at about 30 ° C. and aerobic (dissolved oxygen concentration: about 2 ppm), followed by 48 hours of YPD medium ( Yeast extract / polypeptone / dextrose medium: 10 g / L yeast extract, 20 g / L polypeptone, 20 g / L glucose). The culture supernatant and the cell pellet were separated by centrifugation at 6,000 ⁇ g for 10 minutes at 4 ° C. to obtain a cell pellet.
- synthetic dextrose medium yeast nitrogen source other than 6.7 g / L amino acids (Yeast nitro base without amino acids) [Difco) and appropriate supplements; 20 g / L Of glucose is added as a single carbon source
- the cell pellet is placed in a fermentation medium containing 11.2 g / L PSC, 10 g / L yeast extract, 20 g / L polypeptone, 50 mM citrate buffer (pH 5.0), and 0.5 g / L potassium disulfite. Vaccinated.
- the subsequent fermentation was carried out anaerobically (dissolved oxygen concentration: about 0.05 ppm) at about 30 ° C.
- the cell concentration was adjusted to 75 g / L (wet cells). Since the added PSC is 11.2 g / L, the theoretical yield of ethanol is 5.7 g / L.
- the ethanol concentration during fermentation was measured by HPLC.
- HPLC analysis was performed by using a refractive index (RI) detector (L-2490® RI detector, Hitachi, Ltd.).
- the column used for the separation was Shim-pack SPR-Pb Column (Shimadzu Corporation).
- the HPLC was operated at 80 ° C. with water at a flow rate of 0.6 mL / min as the mobile phase.
- FIG. 8 shows three cellulase surface-displaying yeasts NBRC1440 / EG-CBH2-1c / BGL, NBRC1440 / EG-CBH2-2c / BGL, and NBRC1440 / EG-CBH2 in which the copy numbers of endoglucanase and cellobiohydrolase were sequentially increased. It is a graph which shows the time-dependent change of the amount of ethanol produced
- the left vertical axis represents ethanol concentration (g / L), and the horizontal axis represents elapsed time (hours).
- the black circle is NBRC1440 / EG-CBH2-3c / BGL (3 copies of endoglucanase II and cellobiohydrolase 2)
- the black triangle is NBRC1440 / EG-CBH2-2c / BGL (endoglucanase II and cellobiohydrolase 2)
- the black squares represent the amount of ethanol produced by yeast incorporating NBRC1440 / EG-CBH2-1c / BGL (one copy of both endoglucanase II and cellobiohydrolase 2).
- NBRC1440 / EG-CBH2-3c / BGL which is a yeast incorporating 3 copies of endoglucanase and cellobiohydrolase for 1 copy of ⁇ -glucosidase, is 52.6% of the theoretical yield at 48 h. % Yield.
- Plasmid pRS403 / ssEG2-CBH2 was constructed to have a histidine gene (HIS3) marker and to be incorporated to secrete endoglucanase II (EGII) and cellobiohydrolase 2 (CBH2).
- GAPDH promoter multiple cloning using pUGP3 (Non-patent Document 12) as a template and a primer pair of XYL2c-Xho (F) (SEQ ID NO: 25; Forward) and XYL2c-NotI (R) (SEQ ID NO: 26; Reverse)
- F XYL2c-Xho
- R XYL2c-NotI
- the site (SalI, XbaI, BamHI, SmaI, XmaI) and the gene sequence encoding the GAPDH terminator were PCR amplified.
- the fragment was introduced into the XhoI / NotI site of pRS403 (Stratagene) to obtain plasmid pIHGP3.
- Non-patent Document 10 Using a 1308 bp DNA fragment containing the secretory signal sequence of Rhizopus oryzae-derived glucoamylase gene and Trichoderma reesei-derived endoglucanase (EGII) gene as a template, pEG23u31H6 (Non-patent Document 10), SEQ ID NO: 29 (Forward) and SEQ ID NO: Prepared by PCR using 30 (Reverse) primer pairs.
- the above 1308 bp DNA fragment is digested with SmaI, inserted into the SmaI part of the plasmid pIHGP3 containing the HIS3 gene and its promoter and terminator, GAPDH promoter and GAPDH terminator, and the secretion signal of the HIS3 gene and its promoter and terminator, GAPDH promoter and glucoamylase gene
- a plasmid containing the sequence, EGII gene and GAPDH terminator was obtained.
- the resulting plasmid was named pRS403 / ssEG2.
- the above 1416 bp DNA fragment is digested with SmaI and inserted into the SmaI part of the plasmid pIHGP3 containing the HIS3 gene and its promoter and terminator, GAPDH promoter and GAPDH terminator, and the secretion signal of the HIS3 gene and its promoter and terminator, GAPDH promoter and glucoamylase gene
- a plasmid containing the sequence, CBH2 gene and GAPDH terminator was obtained.
- the resulting plasmid was named pRS403 / ssCBH2.
- a fragment containing a GAPDH (glyceraldehyde triphosphate dehydrogenase) promoter, a secretion signal sequence of a lysopus oryzae-derived glucoamylase gene, a Trichoderma reesei-derived CBH2 gene, and a GAPDH terminator as a primer (SEQ ID NO: 23) ; And Forward and SEQ ID NO: 24; Reverse).
- the resulting fragment was digested with NotI and cloned into pRS403 / ssEG2 digested with NotI.
- the obtained plasmid was designated as pRS403 / ssEG2-CBH2.
- PRS405 (Stratagene) having the LEU2 gene marker was digested with ApaI and NotI, and the fragment obtained above was inserted. The resulting plasmid was named pRS405 / ssCBH2.
- Plasmid pRS403 / ssEG2 was used as a template and amplified by PCR with primers (SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse). The resulting fragment was digested with NotI and cloned into NotI digested pRS405 / ssCBH2. The obtained plasmid was designated as pRS405 / ssEG2-CBH2.
- PRS406 (Stratagene) having the URA3 gene marker was digested with ApaI and NotI, and the fragment obtained above was inserted. The resulting plasmid was named pRS406 / ssCBH2.
- Plasmid pRS403 / ssEG2 was used as a template and amplified by PCR with primers (SEQ ID NO: 23; Forward and SEQ ID NO: 24; Reverse). The resulting fragment was digested with NotI and cloned into pRS406 / ssCBH2 digested with NotI. The obtained plasmid was designated as pRS406 / ssEG2-CBH2.
- Preparation Example 15-4 Preparation of yeast strain into which secretory endoglucanase II and cellobiohydrolase 2 were incorporated at a copy number of 1
- NBRC1440 / UHWL was transformed with pRS406 / ssEG2-CBH2 linearized by cutting with the restriction enzyme NdeI, and a strain having no uracil requirement was selected on a uracil dropout (uracil-free medium) plate.
- the transformation of pRS406 / ssEG2-CBH2 restored the URA3 gene in which NBRC1440 / UHWL was destroyed, confirming the introduction of the gene.
- This strain is named “NBRC1440 / pRS406 / ssEG2-CBH2” and is also abbreviated as “NBRC1440 / ss-EG-CBH2-1c”.
- secretory strains of endoglucanase II and cellobiohydrolase 2 having a copy number of 1 were prepared.
- This strain is named “NBRC1440 / pRS406 / ssEG2-CBH2 / pRS403 / ssEG2-CBH2” and is also abbreviated as “NBRC1440 / ss-EG-CBH2-2c”.
- NBRC1440 / ss-EG-CBH2-2c a copy number 2 endoglucanase II and cellobiohydrolase 2 secretion strain was prepared.
- This strain is named “NBRC1440 / pRS406 / ssEG2-CBH2 / pRS403 / ssEG2-CBH2 / pRS405 ssEG2-CBH2”, and is also abbreviated as “NBRC1440 / ss-EG-CBH2-3c”.
- endoglucanase II and cellobiohydrolase 2 secretion strains having a copy number of 3 were prepared.
- NBRC1440 / ss-EG-CBH2-1c, NBRC1440 / ss-EG-CBH2-2c, and NBRC1440 / ss-EG-CBH2-3c were transformed with pIWBGL that had been cut and linearized with Bst1107I. Strains without tryptophan requirement were selected on tryptophan dropout (tryptophan-free medium) plates. Each disrupted TRP1 gene was restored by transformation with pIWBGL, confirming the introduction of ⁇ -glucosidase 1 gene.
- strains are simplified to NBRC1440 / ss-EG-CBH2-1c / BGL, NBRC1440 / ss-EG-CBH2-2c / BGL, and NBRC1440 / ss-EG-CBH2-3c / Also referred to as “BGL”.
- BGL NBRC1440 / ss-EG-CBH2-3c / Also referred to as “BGL”.
- Example 3 Comparison between cellulase surface display yeast and cellulase-secreting yeast for ethanol production from phosphate-swelled cellulose
- the subsequent fermentation was carried out anaerobically (dissolved oxygen concentration: about 0.05 ppm) at about 30 ° C.
- the cell concentration was adjusted to 75 g / L (wet cells). Since the added PSC is 7.8 g / L, the theoretical yield of ethanol is 4.0 g / L.
- the ethanol concentration during fermentation was measured.
- FIG. 9 is a graph showing changes over time in the amount of ethanol produced from phosphate-swollen cellulose (PSC) in cellulase surface-displaying yeast and cellulase-secreting yeast.
- the horizontal axis of this graph indicates fermentation time (hours), and the vertical axis indicates ethanol production (g / L).
- the black circle is NBRC1440 / ss-EG-CBH2-1c / BGL
- the black triangle is NBRC1440 / ss-EG-CBH2-2c / BGL
- the black square is NBRC1440 / ss-EG-CBH2-3c / BGL
- the white circle is NBRC1440 / EG-CBH2-1c / BGL
- white triangles represent the results of NBRC1440 / EG-CBH2-2c / BGL
- white squares represent the results of NBRC1440 / EG-CBH2-3c / BGL.
- the ethanol fermentation yield from PSC increases as the copy number of endoglucanase and cellobiohydrolase increases with respect to one copy of ⁇ -glucosidase. Indicated.
- a yeast for fermentation that can improve the hydrolysis power of cellulose and enhance ethanol production can be obtained. Therefore, ethanol can be efficiently produced from the cellulosic material, which can lead to cost reduction.
- Such yeast is expected to be used for ethanol production from waste such as soft biomass.
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Abstract
Description
セルロースを加水分解し得る酵素の遺伝子群をセルロース非加水分解性酵母に導入して形質転換酵母を得る工程であって、上記遺伝子群が、結晶性セルロースを加水分解し得る酵素の遺伝子および非晶性セルロースを加水分解し得る酵素の遺伝子を含み、上記結晶性セルロースを加水分解し得る酵素の遺伝子および上記非晶性セルロースを加水分解し得る酵素の遺伝子が共に増大された組み込みコピー数で導入される、工程を含む。
セルロース系物質と、上記セルロース加水分解力強化酵母とを反応させて、エタノールを生産する工程
を含む。
本発明においては、本来セルロースを加水分解する能力がないかまたはほとんどない酵母(野生型酵母など)(本明細書中では、「セルロース非加水分解性酵母」ともいう)に対して、セルロースを加水分解し得る酵素群を発現するように遺伝子組換えを行うことにより、セルロース加水分解力が強化された形質転換酵母が作製される。
上述したようなセルロース加水分解力強化酵母は、エタノールの生産に好適に使用され得る。エタノールの生産のために、セルロース加水分解力強化酵母をセルロース基質(例えば、以下に説明するようなセルロース系物質)に反応させ得る。
(調製例1-1:URA3マーカーの付与)
変異URA3断片を、サッカロマイセス・セレビシエMT8-1(MATa ade his3 leu2 trp1 ura3)から、配列番号1および配列番号2で示されるプライマー対を用いてPCRにより取得した。この断片をサッカロマイセス・セレビシエNBRC1440(MATα)株に形質転換し、5-フルオロオロト酸(FOA)培地でURA3変異株を選択し、URA3マーカーが付与されたNBRC1440株を得た。
以下のようにして融合PCRを実施した:
PCR1、HIS3-Green U(配列番号3;Forward)およびHIS3-Green R(配列番号4;Reverse)プライマーを用いて、サッカロマイセス・セレビシエNBRC1440株の染色体DNAを鋳型として用いてHIS3上流部分配列を増幅した;
PCR2、URA3 fragment(配列番号5;Forward)およびHIS3-40Uc(配列番号6;Reverse)プライマーを用いて、鋳型としてpRS406プラスミド(Stratagene社)を鋳型として用いてURA3を増幅した;
PCR3、HIS3-Green U(配列番号3;Forward)およびHIS3-40Uc(配列番号6;Reverse)プライマーを用いて、鋳型としてPCR1およびPCR2での産物を混合することにより融合フラグメントを増幅した。
以下のようにして融合PCRを実施した:
PCR1、TRP1-988(配列番号7;Forward)およびRP1-28r(配列番号8;Reverse)プライマーを用いて、サッカロマイセス・セレビシエNBRC1440株の染色体DNAを鋳型として用いてTRP1上流部分配列を増幅した;
PCR2、TRP1-URA3(配列番号9;Forward)およびTRP1-40r(配列番号10;Reverse)プライマーを用いて、鋳型としてpRS406プラスミド(Stratagene社)を鋳型として用いてURA3を増幅した;
PCR3、TRP1-988(配列番号7;Forward)およびTRP1-40r(配列番号10;Reverse)プライマーを用いて、鋳型としてPCR1およびPCR2での産物を混合することにより融合フラグメントを増幅した。
以下のようにして融合PCRを実施した:
PCR1、LEU2-UP 3rd(配列番号11;Forward)およびLEU2-down 3rd(配列番号12;Reverse)プライマーを用いて、サッカロマイセス・セレビシエNBRC1440株の染色体DNAを鋳型として用いてLEU2上流部分配列を増幅した;
PCR2、LEU2-URA3 3rd(配列番号13;Forward)およびLEU2-40r(配列番号14;Reverse)プライマーを用いて、鋳型としてpRS406プラスミド(Stratagene社)を鋳型として用いてURA3を増幅した;
PCR3、LEU2-UP 3rd(配列番号11;Forward)およびLEU2-40r(配列番号14;Reverse)プライマーを用いて、鋳型としてPCR1およびPCR2での産物を混合することにより融合フラグメントを増幅した。
まず、ウラシル遺伝子(URA3)マーカーを有し、かつトリコデルマ・リーセイ(Trichoderma reesei)由来エンドグルカナーゼII(EGII)遺伝子を表層提示されるように組み込むためのプラスミドpGK406 EGを構築した。
まず、ヒスチジン遺伝子(HIS3)マーカーを有し、かつトリコデルマ・リーセイ由来エンドグルカナーゼII(EGII)遺伝子を表層提示されるように組み込むためのプラスミドpGK403 EGを構築した。
まず、ロイシン遺伝子(LEU2)マーカーを有し、かつトリコデルマ・リーセイ由来エンドグルカナーゼII(EGII)遺伝子を表層提示されるように組み込むためのプラスミドpGK405 EGを構築した。
pUGP3(非特許文献12)を鋳型として、XYL2c-XhoI(F)(配列番号25;Forward)およびXYL2c-NotI(R)(配列番号26;Reverse)のプライマー対を用いて、GAPDHプロモーター、マルチクローニングサイト(SalI, XbaI, BamHI, SmaI, XmaI)、およびGAPDHターミネーターをコードする遺伝子配列をPCR増幅した。その断片をpRS405(Stratagene)のXhoI/NotIサイトに導入してプラスミドpILGP3を得た。
プラスミドpFCBH2w3をテンプレートとし、GAPDH(グリセルアルデヒド三リン酸デヒドロゲナーゼ)プロモーター、リゾプス・オリゼ由来グルコアミラーゼ遺伝子の分泌シグナル配列とトリコデルマ・リーセイ由来CBH2遺伝子とα-アグルチニン遺伝子の3’側半分の領域、GAPDHターミネーターを含む断片をプライマー(配列番号23;Forwardおよび配列番号24;Reverse)によりPCRで増幅した。得られた断片をNotIで消化し、そしてNotIで消化したpILGP3-CBH2にクローニングした。得られたプラスミドをpRS405 CBH2 CBH2とし、その模式図を図5に示す。図5中、「LEU2」はロイシン遺伝子マーカーを表し、それ以外の表記は図1と同様である。
アスペルギルス・アクレアタス(Aspergillus aculeatus)由来β-グルコシダーゼ1(BGL1)遺伝子をコードする2.5kbp NcoI-XhoI DNAフラグメントを、プラスミドpBG211(京都大学より贈与戴いた)を鋳型として使用し、bgl1プライマー1(配列番号27;Forward)およびbgl1プライマー2(配列番号28;Reverse)のプライマー対を用いてPCRによって調製した。このDNAフラグメントをNcoIおよびXhoIで消化し、リゾプス・オリゼ由来グルコアミラーゼ遺伝子の分泌シグナル配列およびα-アグルチニン遺伝子の3’側半分の領域(非特許文献9)を含有する細胞表層発現プラスミドpIHCS(非特許文献10)のNcoI-XhoI部位に挿入した。得られたプラスミドをpIBG13と命名した。
制限酵素NdeIで切断して直線状にしたpGK406 EGで、NBRC1440/UHWLを形質転換し、ウラシルドロップアウト(ウラシル不含培地)プレート上でウラシル要求性を持たない株を選択した。pGK406 EGでの形質転換により、NBRC1440/UHWLの破壊されたURA3遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/pGK406 EG」と命名した。本調製例8では、コピー数1のエンドグルカナーゼIIの表層提示株を作製した。
制限酵素NdeIで切断して直線状にしたpRS406 EG CBH2で、NBRC1440/UHWLを形質転換し、ウラシルドロップアウト(ウラシル不含培地)プレート上でウラシル要求性を持たない株を選択した。pRS406 EG CBH2での形質転換により、NBRC1440/UHWLの破壊されたURA3遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/pRS406 EG CBH2」と命名し、簡略化して「NBRC1440/EG-CBH2-1c」とも表記する。本調製例9では、コピー数1のエンドグルカナーゼIIおよびセロビオヒドロラーゼ2の表層提示株を作製した。
制限酵素NdeIで切断して直線状にしたpRS403 EG CBH2で、NBRC1440/pRS406 EG CBH2を形質転換し、ヒスチジンドロップアウト(ヒスチジン不含培地)プレート上でヒスチジン要求性を持たない株を選択した。pRS403 EG CBH2での形質転換により、NBRC1440/pRS406 EG CBH2の破壊されたHIS3遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/pRS406 EG CBH2/pRS403 EG CBH2」と命名し、簡略化して「NBRC1440/EG-CBH2-2c」とも表記する。本調製例10では、コピー数2のエンドグルカナーゼIIおよびセロビオヒドロラーゼ2の表層提示株を作製した。
制限酵素HpaIで切断して直線状にしたpRS405 EG CBH2で、NBRC1440/pRS406 EG CBH2/pRS403 EG CBH2を形質転換し、ロイシンドロップアウト(ロイシン不含培地)プレート上でロイシン要求性を持たない株を選択した。pRS405 EG CBH2での形質転換により、NBRC1440/pRS406 EG CBH2/pRS403 EG CBH2の破壊されたLEU2遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/pRS406 EG CBH2/pRS403 EG CBH2/pRS405 EG CBH2」と命名し、簡略化して「NBRC1440/EG-CBH2-3c」とも表記する。本調製例11では、コピー数3のエンドグルカナーゼIIおよびセロビオヒドロラーゼ2の表層提示株を作製した。
制限酵素HpaIで切断して直線状にしたpILGP3-CBH2で、NBRC1440/pRS406 EG CBH2を形質転換し、ロイシンドロップアウト(ロイシン不含培地)プレート上でロイシン要求性を持たない株を選択した。pILGP3-CBH2での形質転換により、NBRC1440/EG-CBH2-1cの破壊されたLEU2遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/pRS406 EG CBH2/pILGP3-CBH2」と命名し、簡略化して「NBRC1440/EG-CBH2-1c-CBH2」とも表記する。本調製例12では、コピー数1のエンドグルカナーゼIIおよびコピー数2のセロビオヒドロラーゼ2の表層提示株を作製した。
制限酵素HpaIで切断して直線状にしたpRS405 CBH2 CBH2で、NBRC1440/pRS406 EG CBH2を形質転換し、ロイシンドロップアウト(ロイシン不含培地)プレート上でロイシン要求性を持たない株を選択した。pRS405 CBH2 CBH2での形質転換により、NBRC1440/EG-CBH2-1cの破壊されたLEU2遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/pRS406 EG CBH2/pRS405 CBH2 CBH2」と命名し、簡略化して「NBRC1440/EG-CBH2-1c-CBH2×2」とも表記する。本調製例13では、コピー数1のエンドグルカナーゼIIおよびコピー数3のセロビオヒドロラーゼ2の表層提示株を作製した。
Bst1107Iで切断して直線状にしたpIWBGLで、NBRC1440/EG-CBH2-1c(調製例9)、NBRC1440/EG-CBH2-2c(調製例10)、およびNBRC1440/EG-CBH2-3c(調製例11)のそれぞれを形質転換した。トリプトファンドロップアウト(トリプトファン不含培地)プレート上でトリプトファン要求性を持たない株を選択した。pIWBGLでの形質転換により、各々の破壊されたTRP1遺伝子が復活することで、β-グルコシダーゼ1遺伝子の導入を確認した。したがって、コピー数1、2、または3のエンドグルカナーゼIIおよびセロビオヒドロラーゼ2の表層提示株にさらにβ-グルコシダーゼ1を表層提示した株が得られた。得られたそれぞれの形質転換株を、簡略化して、「NBRC1440/EG-CBH2-1c/BGL」、「NBRC1440/EG-CBH2-2c/BGL」、および「NBRC1440/EG-CBH2-3c/BGL」と表記する(便宜上、これらの形質転換株を「セルラーゼ表層提示酵母」ともいう)。
上記調製例8から13で得られた各種酵母を、リン酸膨潤セルロース(PSC;非特許文献13により調製)と反応させることにより、それらのセルロース加水分解力を測定した。反応条件は次の通りである:50mM クエン酸緩衝液、10mg/mL PSC、酵母OD600=3.0、反応時間24時間。活性測定は、PSCを分解させ生じた還元糖をソモギ・ネルソン法により定量した。酵母1g当たり、1分間に1μモルのグルコースに相当する還元力を生成する活性を1Uとした。
NBRC1440(図中「1440」)、
NBRC1440/pGK406 EG(図中「EG」;調製例8:コピー数1のエンドグルカナーゼIIを組み込んだ酵母株)、
NBRC1440/EG-CBH2-1c(図中「EG CBH2」;調製例9:エンドグルカナーゼIIとセロビオヒドロラーゼ2とを共にコピー数1で組み込んだ酵母株)、
NBRC1440/EG-CBH2-1c-CBH2(図中「EG CBH2」の「CBH2」;調製例12:エンドグルカナーゼIIとセロビオヒドロラーゼ2とを共にコピー数1で組み込み、さらにコピー数1のセロビオヒドロラーゼ2を組み込んだ酵母株)、
NBRC1440/EG-CBH2-1c-CBH2×2(図中「EG CBH2」の「CBH2×2」;調製例13:エンドグルカナーゼIIとセロビオヒドロラーゼ2とを共にコピー数1で組み込み、さらにコピー数2のセロビオヒドロラーゼ2を組み込んだ酵母株)、
NBRC1440/EG-CBH2-2c(図中「EG CBH2」の「×2」;調製例10:エンドグルカナーゼIIとセロビオヒドロラーゼ2とを共にコピー数2で組み込んだ酵母株)、および
NBRC1440/EG-CBH2-3c(図中「EG CBH2」の「×3」;調製例11:エンドグルカナーゼIIとセロビオヒドロラーゼ2とを共にコピー数3で組み込んだ酵母株)。
実施例1では、「EG CBH2」の組み合わせでコピー数を増加させるごとにPSC分解活性が上昇した。よって、本実施例では、「EG CBH2」の2カセット(EGおよびCBH2の2つの遺伝子カセット)のベクターを1コピー、2コピー、および3コピー組み込んだ株をそれぞれ用いてPSCからのエタノール発酵を行った。
以下に、β-グルコシダーゼを表層提示するが、エンドグルカナーゼおよびセロビオヒドロラーゼを分泌するように組み込んだ酵母(これを、便宜上、「セルラーゼ分泌酵母」ともいう)の調製手順を説明する。
ヒスチジン遺伝子(HIS3)マーカーを有し、かつエンドグルカナーゼII(EGII)およびセロビオヒドロラーゼ2(CBH2)を分泌させるように組み込むためのプラスミドpRS403/ssEG2-CBH2を構築した。
GAPDHプロモーター、リゾプス・オリゼ由来グルコアミラーゼ遺伝子の分泌シグナル配列、セロビオヒドロラーゼ2(CBH2)遺伝子およびGAPDHターミネーターを含む断片を、pRS403/ssCBH2をApaIおよびNotIで消化することで得た。
GAPDHプロモーター、リゾプス・オリゼ由来グルコアミラーゼ遺伝子の分泌シグナル配列、セロビオヒドロラーゼ2(CBH2)遺伝子およびGAPDHターミネーターを含む断片を、pRS403/ssCBH2をApaIおよびNotIで消化することで得た。
制限酵素NdeIで切断して直線状にしたpRS406/ssEG2-CBH2で、NBRC1440/UHWLを形質転換し、ウラシルドロップアウト(ウラシル不含培地)プレート上でウラシル要求性を持たない株を選択した。pRS406/ssEG2-CBH2での形質転換により、NBRC1440/UHWLの破壊されたURA3遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/ pRS406/ssEG2-CBH2」と命名し、簡略化して「NBRC1440/ss-EG-CBH2-1c」とも表記する。本調製例では、コピー数1のエンドグルカナーゼIIおよびセロビオヒドロラーゼ2の分泌株を作製した。
制限酵素NdeIで切断して直線状にしたpRS403/ssEG2-CBH2で、NBRC1440/ pRS406/ssEG2-CBH2を形質転換し、ヒスチジンドロップアウト(ヒスチジン不含培地)プレート上でヒスチジン要求性を持たない株を選択した。pRS406/ssEG2-CBH2での形質転換により、NBRC1440/ pRS406/ssEG2-CBH2の破壊されたHIS3遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/ pRS406/ssEG2-CBH2/ pRS403/ssEG2-CBH2」と命名し、簡略化して「NBRC1440/ss-EG-CBH2-2c」とも表記する。本調製例では、コピー数2のエンドグルカナーゼIIおよびセロビオヒドロラーゼ2の分泌株を作製した。
制限酵素HpaIで切断して直線状にしたpRS405 ssEG2-CBH2で、NBRC1440/ pRS406/ssEG2-CBH2/ pRS403/ssEG2-CBH2を形質転換し、ロイシンドロップアウト(ロイシン不含培地)プレート上でロイシン要求性を持たない株を選択した。pRS405 ssEG2-CBH2での形質転換により、NBRC1440/ pRS406/ssEG2-CBH2/ pRS403/ssEG2-CBH2の破壊されたLEU2遺伝子が復活することで、遺伝子の導入を確認した。この株を「NBRC1440/ pRS406/ssEG2-CBH2/ pRS403/ssEG2-CBH2/ pRS405 ssEG2-CBH2」と命名し、簡略化して「NBRC1440/ss-EG-CBH2-3c」とも表記する。本調製例では、コピー数3のエンドグルカナーゼIIおよびセロビオヒドロラーゼ2の分泌株を作製した。
Bst1107Iで切断して直線状にしたpIWBGLで、NBRC1440/ss-EG-CBH2-1c、NBRC1440/ss-EG-CBH2-2c、およびNBRC1440/ss-EG-CBH2-3cを形質転換した。トリプトファンドロップアウト(トリプトファン不含培地)プレート上でトリプトファン要求性を持たない株を選択した。pIWBGLでの形質転換により、各々の破壊されたTRP1遺伝子が復活することで、β-グルコシダーゼ1遺伝子の導入を確認した。これらの株を簡略化して、それぞれ、「NBRC1440/ss-EG-CBH2-1c/BGL」、「NBRC1440/ss-EG-CBH2-2c/BGL」、および「NBRC1440/ss-EG-CBH2-3c/BGL」とも表記する。本調製例では、調製例15-4から15-6の分泌株においてさらに、1コピーのβ-グルコシダーゼを表層提示するようにした株を作製した。
セルラーゼ表層提示酵母(調製例14)のNBRC1440/EG-CBH2-1c/BGL、NBRC1440/EG-CBH2-2c/BGL、およびNBRC1440/EG-CBH2-3c/BGL、ならびにセルラーゼ分泌酵母(調製例15)のNBRC1440/ss-EG-CBH2-1c/BGL、NBRC1440/ss-EG-CBH2-2c/BGL、およびNBRC1440/ss-EG-CBH2-3c/BGLのいずれかの細胞ペレットを、7.8g/LのPSC、10g/Lの酵母エキス、10g/Lのポリペプトン、50mM クエン酸緩衝液(pH 5.0)、および0.5g/Lの二亜硫酸カリウムを含有する発酵培地に接種した。続く発酵は、約30℃にて嫌気的(溶存酸素濃度:約0.05ppm)に実施した。発酵開始時には細胞濃度を75g/L(湿潤細胞)に調整した。加えたPSCが7.8g/Lであることより、エタノールの理論収率は4.0g/Lとなる。実施例2と同様にして、発酵中のエタノール濃度の測定を行った。
Claims (11)
- セルロース加水分解力強化酵母を作製する方法であって、
セルロースを加水分解し得る酵素の遺伝子群をセルロース非加水分解性酵母に導入して形質転換酵母を得る工程であって、該遺伝子群が、結晶性セルロースを加水分解し得る酵素の遺伝子および非晶性セルロースを加水分解し得る酵素の遺伝子を含み、該結晶性セルロースを加水分解し得る酵素の遺伝子および該非晶性セルロースを加水分解し得る酵素の遺伝子が共に増大された組み込みコピー数で導入される、工程
を含む、方法。 - 前記結晶性セルロースを加水分解し得る酵素がセロビオヒドロラーゼであり、前記非晶性セルロースを加水分解し得る酵素がエンドグルカナーゼである、請求項1に記載の方法。
- 前記結晶性セルロースを加水分解し得る酵素および前記非晶性セルロースを加水分解し得る酵素の少なくとも一方が表層提示されるように前記セルロース非加水分解性酵母に導入する、請求項1または2に記載の方法。
- 前記セルロースを加水分解し得る酵素の遺伝子群が、セロビオースまたはセロオリゴ糖を加水分解し得る酵素の遺伝子をさらに含む、請求項1から3のいずれかに記載の方法。
- 前記セロビオースまたはセロオリゴ糖を加水分解し得る酵素の遺伝子の組み込みコピー数の1コピーに対し、前記結晶性セルロースを加水分解し得る酵素および前記非晶性セルロースを加水分解し得る酵素のそれぞれの遺伝子の組み込みコピー数が少なくとも2コピーである、請求項4に記載の方法。
- 前記セロビオースまたはセロオリゴ糖を加水分解し得る酵素がβ-グルコシダーゼである、請求項4または5に記載の方法。
- 前記セロビオースまたはセロオリゴ糖を加水分解し得る酵素が表層提示されるように前記セルロース非加水分解性酵母に導入する、請求項4から6のいずれかに記載の方法。
- 請求項1から7のいずれかに記載の方法により得られる、セルロース加水分解力強化酵母。
- セロビオヒドロラーゼ遺伝子、エンドグルカナーゼ遺伝子、およびβ-グルコシダーゼ遺伝子を有し、該β-グルコシダーゼ遺伝子1コピーに対して、該セロビオヒドロラーゼ遺伝子および該エンドグルカナーゼ遺伝子のそれぞれが少なくとも2コピーで組み込まれた、セルロース加水分解力強化酵母。
- 前記セロビオヒドロラーゼ、前記エンドグルカナーゼ、および前記β-グルコシダーゼが表層提示されている、請求項9に記載のセルロース加水分解力強化酵母。
- エタノールを製造する方法であって、
セルロース系物質と、請求項8から10のいずれかに記載のセルロース加水分解力強化酵母とを反応させて、エタノールを生産する工程
を含む、方法。
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US13/063,225 US8574911B2 (en) | 2008-09-17 | 2009-09-16 | Production and use of yeast having increased cellulose hydrolysis ability |
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US9816113B2 (en) | 2013-09-04 | 2017-11-14 | Kansai Chemical Engineering Co., Ltd. | Method for producing ethanol |
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US9850512B2 (en) | 2013-03-15 | 2017-12-26 | The Research Foundation For The State University Of New York | Hydrolysis of cellulosic fines in primary clarified sludge of paper mills and the addition of a surfactant to increase the yield |
US9951363B2 (en) | 2014-03-14 | 2018-04-24 | The Research Foundation for the State University of New York College of Environmental Science and Forestry | Enzymatic hydrolysis of old corrugated cardboard (OCC) fines from recycled linerboard mill waste rejects |
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Non-Patent Citations (3)
Title |
---|
"Abstracts of Autumn Meeting of the Society of Chemical Engineers, Japan, Aug.2008", vol. 40, article SHUHEI YANASE ET AL.: "Cellulase Hatsugen Kobo ni yoru Cellulose kara no Bioethanol Seisan", pages: X160 * |
FUJITA, Y. ET AL.: "Synergistic Saccharification, and Direct Fermentation to Ethanol, of Amorphous Cellulose by Use of an Engineered Yeast Strain Codisplaying Three Types of Cellulolytic Enzyme.", APPLIED AND ENVIRONMENTAL MICROBIOLOGY, vol. 70, no. 2, 2004, pages 1207 - 1212 * |
TSUTOMU TANAKA ET AL.: "Saibo Hyoso Teiji Gijutsu o Mochiita Biseibutsu no Kokinoka to Yuyo Bussitsu Seisan", BIO INDUSTRY, vol. 25, no. 8, August 2008 (2008-08-01), pages 13 - 19 * |
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JP2012139211A (ja) * | 2010-12-16 | 2012-07-26 | Kobe Univ | エタノールの生産方法 |
WO2013146540A1 (ja) * | 2012-03-26 | 2013-10-03 | 関西化学機械製作株式会社 | エタノールの生産方法 |
JPWO2013146540A1 (ja) * | 2012-03-26 | 2015-12-14 | Bio−energy株式会社 | エタノールの生産方法 |
US9580729B2 (en) | 2012-03-26 | 2017-02-28 | Kansai Chemical Engineering Co., Ltd. | Method for producing ethanol |
US9816113B2 (en) | 2013-09-04 | 2017-11-14 | Kansai Chemical Engineering Co., Ltd. | Method for producing ethanol |
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