JP2008178355A - Method for producing ethanol and lactic acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently obtain ethanol and lactic acid and stably at low cost, and to provide a method for producing them. <P>SOLUTION: The method for producing ethanol comprises the processes, wherein Sap, as a composition collected from oil palm trunks 10 cut down, is fermented by microorganisms. Alternatively, the above sap is mixed with a mixed syrup of a monosaccharide and an oligosaccharide that are obtained by hydrolysis of the fibers of oil palm trunks, after collecting the sap and the resulting mixture, may be fermented by microorganisms. The method for producing lactic acid comprises the process, wherein Sap, as a composition collected from oil palm trunks 10 cut down, is fermented by microorganisms. Alternatively, the above sap is mixed with a mixed syrup of monosaccharide and oligosaccharide that are obtained by hydrolysis of the fibers of oil palm trunks, after collecting the sap and the resulting mixture may be fermented, by microorganisms. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to ethanol and lactic acid and methods for producing them, and more particularly to ethanol and lactic acid that can be produced from oil palm trunk at high yield and at low cost, and methods for producing these.

  Palm oil is produced around 35.5 million tons / year in the world, of which 87% is a representative agricultural product in Southeast Asia, half of which is Malaysia and Indonesia (2005 results, US Department of Agriculture statistics) (According to material). Since palm oil is less expensive than soybean oil, it is used not only for foods such as margarine and fried oil but also for industrial use such as soap and cosmetics.

  Oil palm (oil palm, scientific name: Elaeis guineensis, Japanese name: oil palm) cultivated for palm oil production requires replanting at intervals of 20-25 years in order to maintain productivity . In Malaysia, about 40 million hectares of replanting is currently being carried out annually since 1980, and about 30 million tons of palm trunks have been cut down. In the near future, it is expected that about 200,000 to 250,000 hectares of replanting will be required every year as a result of the expansion of plantation area. Felled oil palm by replanting is used by injecting drugs into the trunk and withering, or leaving or incineration in the plantation after logging, and there is concern that it may lead to serious environmental destruction, and it will not cause environmental impact There is a need to develop laws.

  Unlike other woody biomass, the oil palm trunk is made up of vascular bundles and fibers surrounding the vascular bundle. Therefore, the durability as wood is inadequate, and as a method of use, a relatively strong outer skin is used as a surface processing material such as plywood, and other parts are unused and discarded. It is necessary to develop an effective use of the inner part of the trunk as soon as possible.

On the other hand, in recent years, development of production technologies for bioplastic raw materials such as petroleum alternative energy such as ethanol for fuel and lactic acid has been actively conducted as a measure for reducing the depletion of petroleum resources and global warming. In particular, ethanol for fuel has attracted attention as an alternative fuel for gasoline, which is an automobile fuel, and its demand is very large.
However, at present, most fuel ethanol is produced from edible agricultural products such as corn starch and sugarcane juice, and competition between food applications and energy applications arises due to an increase in demand for edible agricultural products accompanying future population growth. It is expected. For this reason, development of technology for converting unused crops, that is, agricultural waste to ethanol for fuels, is desired, but technical development is still extremely difficult. The felled oil palm trunk is a very promising biomass resource from the viewpoint of the amount produced, the sustainable development of the oil palm industry and the reduction of environmental impact.

  From such a background, Patent Document 1 discloses a method for producing a vegetable fiber powder food containing hemicellulose, cellulose, and lignin by pulverizing the fiber of a felled oil palm trunk. Does not disclose a method for producing ethanol or lactic acid from an oil palm trunk.

  Patent Document 2 discloses a method for producing a feed comprising cellulose fiber waste of oil palm. Cellulose fiber, empty fruit bunch, pulp fiber, etc. are used as this waste. . However, Patent Document 2 does not disclose a method for producing ethanol or lactic acid from an oil palm trunk.

  Patent Document 3 discloses a method for producing a functional food by pulverizing fiber powder composed of oil palm leaves. However, Patent Document 3 does not disclose a method for producing ethanol or lactic acid from an oil palm trunk.

  Non-Patent Document 1 reports an attempt to produce ethanol from sugar obtained by hydrolyzing the oil palm fiber.

JP-A-8-221 JP-A-9-168367 JP 2005-218425 A H.H. Yeoh et al., “Fermentation of oil palm trunk acid hydrolysate to ethanol”, ASEAN Journal on Science and Technology for Development, 2001, 18 (1), p. 1-10

  Non-Patent Document 1 reports that ethanol is produced from sugar obtained by hydrolyzing fiber, but it is far from practical use due to poor hydrolysis efficiency and low sugar recovery rate. There is a problem.

  There is a strong demand for cost reduction in the production of lactic acid, which is a raw material for bioplastics, but it is currently produced from expensive edible agricultural products such as corn starch, and it is difficult to reduce the cost. In order to reduce the price of lactic acid, it is necessary to develop manufacturing technology using raw agricultural products. However, there has been no report on a technique for producing lactic acid using an oil palm trunk so far.

  In view of the above problems, an object of the present invention is to provide ethanol and lactic acid that can be obtained efficiently and stably at low cost, and methods for producing them.

  As a result of extensive research, the inventors of the present invention have greatly different free sugar compositions and contents in the sap obtained from each part from the central region to the outer region of the oil palm trunk. We found that free sugars were present. Based on this knowledge, we succeeded in producing ethanol and lactic acid by fermentation using raw oil sap, which is a composition obtained from oil palm trunk and oil palm trunk after cutting, and completed the present invention. It was. In addition, after collecting sap from the oil palm trunk, the fiber surrounding the vascular bundle is treated with an enzyme, and the resulting sugar and sap are mixed to prepare a large amount of sugar that can be fermented by the microorganism. Succeeded in producing ethanol and lactic acid respectively using the above, and reached the present invention.

In order to achieve the first object, the ethanol production method of the present invention is characterized in that ethanol is obtained by fermenting a composition other than oil palm trunk-derived bark with a microorganism. This composition preferably consists of sap.
In the present invention, in particular, the sap collected from the oil palm trunk, or the sap thereof, and the monosaccharide or oligosaccharide obtained by hydrolyzing the fiber of the oil palm trunk after collecting the sap are mixed, and the mixture It is characterized by producing ethanol by fermentation with microorganisms.
In the said structure, you may ferment the free sugar obtained by isolate | separating from a composition or sap. It is preferable to use one or more microorganisms selected from the group consisting of bacteria and yeast.
The ethanol of the present invention is produced using any of the above production methods.

  According to the said structure, ethanol is obtained from the composition derived from an oil palm trunk as a raw material, and ethanol can be stably manufactured with high yield and low cost.

In order to achieve the second object, the method for producing lactic acid according to the present invention is characterized in that lactic acid is obtained by fermenting a composition other than oil palm trunk-derived bark with a microorganism. This composition preferably consists of sap.
In the present invention, in particular, sap collected from oil palm trunk and monosaccharide or oligosaccharide obtained by hydrolyzing the oil palm trunk fiber after collecting sap are mixed, and the mixture is fermented with microorganisms. It is characterized by producing lactic acid.
In the said structure, you may ferment the free sugar obtained by isolate | separating from a composition or sap. It is preferable to use one or more microorganisms selected from the group consisting of bacteria and yeast.
The lactic acid of the present invention is produced using any of the above production methods.

  According to the said structure, lactic acid is obtained from the composition derived from an oil palm trunk as a raw material, and it can manufacture lactic acid stably with a high yield at low cost.

  According to the method for producing ethanol of the present invention, ethanol can be produced stably at a high yield and at low cost using a composition other than the bark derived from oil palm trunk as a raw material. The ethanol obtained by this production method may be mixed with gasoline as an alternative energy for petroleum, and can be used as a gasoline additive such as ethyl tertiary butyl ether and other chemical raw materials such as ethylene, as well as food and food. As additives, it can be used for the production of beer, distilled liquor and other alcoholic beverages, soft drinks, pickles, soy sauce, etc., and for the production of pharmaceuticals and quasi drugs.

  According to the method for producing lactic acid of the present invention, lactic acid can be produced stably at a high yield and at low cost using a composition other than the bark derived from oil palm trunk as a raw material. Lactic acid obtained by this method is not only used as a raw material for polylactic acid, a biodegradable plastic, but also as a food additive, for producing beer, distilled liquor and other alcoholic beverages, soft drinks, pickles, soy sauce, etc. It can also be used for the manufacture of quasi-drugs and quasi-drugs.

  In any of the above production methods, the cutting oil that has been treated only as waste in the past can be produced not only from the bark of the palm trunk, but also from ethanol and lactic acid at a high yield and low cost. Resource value for palm trunks can be increased, and a sustainable oil palm industry can be established and environmental burdens can be reduced.

The best mode for carrying out the present invention will be described below with reference to the drawings.
The method for producing ethanol and the method for producing lactic acid according to the present invention use a composition other than bark collected from an oil palm trunk or a felled oil palm trunk as a raw material, and ferment the raw material with a microorganism to produce ethanol or lactic acid. It is characterized by obtaining. The composition is composed of a sap or a fibrous composition collected or extracted from an oil palm trunk or a felled oil palm trunk. First, the oil palm trunk used in the method for producing ethanol and the method for producing lactic acid of the present invention and a composition derived from this oil palm trunk will be described. In the following description, a composition other than the bark is simply referred to as a composition.

  In the present invention, an oil palm trunk is used as a material or a raw material. Any of young trees, mature trees, and old trees can be applied, but oil palm trunks with reduced oil palm fruit productivity, oil palm trunks that have passed 20 years or more, and felled oil palm trunks are particularly preferable. It is also possible to use an oil palm trunk that has been young and has an oil palm fruit productivity, which has been cut for replanting or planned cultivation, or an oil palm trunk that must be cut by a pest. Any oil palm trunk can be used as long as it can collect a composition comprising the above.

  As a technique for collecting a composition such as sap from an oil palm trunk, physical compression, pulverization, drying, and centrifugation, heating with water vapor, addition of water, or extraction with an organic solvent can be used. Chemical treatment may be applied to facilitate collection of sap. In particular, it is preferable to obtain a sap or fiber by crushing the felled oil palm trunk and then physically squeezing it, but any method may be adopted as long as it can be collected.

  It is preferable to collect the sap immediately after logging. Depending on the amount and / or state of free sugar contained in the sap, it may be left for several months, preferably for several weeks, particularly preferably for several days after logging. The sap may be collected by adopting the above method from an oil palm trunk stored in a state of freezing, refrigeration, heating, steaming, vacuuming, chemical treatment, or the like.

FIG. 1A is a perspective view of a ring obtained by cutting an oil palm trunk from which sap is collected in a direction perpendicular to the axial direction, and FIG. 1B is a cross-sectional view taken along the line XX in FIG.
As shown in FIG. 1, the oil palm trunk 10 from which the sap is collected is divided into tree trunk portions including a central area 11, an intermediate area 12, and an outer area 13. The outermost surface is the bark 14. When the cross-sectional diameter of the oil palm trunk 10 is about 33 cm, the central region 11 is a region extending about 5 to 8 cm away from the central axis, and the intermediate region 12 is about 5 cm outward from the central region. The bark 14 has a thickness of about 2 to 3 cm, and the remainder is the outer region 13. In order to extract the composition derived from the oil palm trunk 10 made of sap or the like, it is preferable to extract from the central area 11 of the oil palm trunk 10, but the central area 11 and the intermediate area 12 depending on the situation of the oil palm trunk 10. May be taken from Furthermore, you may extract | collect from the outer side area | region 13, the intermediate | middle area | region 12, and the center area | region 11.

  Here, the sap which is a composition other than the bark collected from the oil palm trunk using the above method in the present invention, the free sugar obtained by separation or separation and extraction from the sap, and the vascular bundle after collecting the sap The remaining carbohydrate may be recovered by extracting any of the fiber residues or a mixture thereof with water, an organic solvent, or the like. At that time, the extraction may be performed by heating, cooling, and pH fluctuations under such conditions that the saccharide is not decomposed. The saccharide extracted from the recovered fiber residue may be used together with the sap already collected.

  Further, after collecting the sugar remaining in the fiber, the saccharide bundle obtained by hydrolysis of the vascular bundle of the oil palm trunk and the saccharide remaining in the fiber surrounding the vascular bundle may be used. That is, using the vascular bundle and the fiber surrounding the vascular bundle existing in the central region 11, the intermediate region 12, and the outer region 13 of the oil palm trunk 10 shown in FIG. To obtain monosaccharides and oligosaccharides.

  Here, depending on the state of the fiber, it may be directly hydrolyzed by the above enzyme, but pretreatment using heat or chemicals in order to obtain the maximum enzyme treatment effect before performing the enzymatic hydrolysis. It is preferable to carry out. Specifically, the fiber is treated with sulfuric acid, hydrochloric acid, nitric acid or other acidic or sodium hydroxide, potassium hydroxide, ammonia, urea or other alkaline chemicals for a long time at room temperature or at a high temperature for 10 minutes to 2 minutes. It is preferable to perform the heat treatment with a reaction time of about an hour.

  Specifically, the case of sulfuric acid will be described as an example. The sulfuric acid concentration is 0.1 to 5%, preferably about 0.5 to 3%, and the heating temperature is 140 ° C to 230 ° C, preferably 160 ° C to 210 ° C. The reaction time is about 1 to 20 minutes, preferably about 5 to 10 minutes. These pretreatments are preferably performed using an autoclave or the like.

  As soon as the pretreatment is completed, neutralization is performed. If the pre-treatment product is acidic, neutralize with alkaline chemicals such as sodium hydroxide, calcium hydroxide, potassium hydroxide, urea, ammonia, etc. If the pre-treatment product is alkaline, hydrochloric acid, sulfuric acid, nitric acid Neutralize with acidic chemicals such as

  After neutralization, cellulase and hemicellulase, which are enzymes, are added to the neutralized pretreated product, and the mixture is allowed to stand or stirred under conditions of pH 4-6, temperature 35-60 ° C, 10-100 hours. Enzymatic hydrolysis reaction. The secondary sugar solution obtained by this enzymatic hydrolysis includes cellulose, hemicellulose-derived sugars such as glucose, xylose, arabinose, galactose, rhamnose, mannose and oligosaccharides composed of these components.

  As a method for more efficiently saccharifying the fiber from the oil palm trunk, it is possible to obtain a saccharide even by subjecting it to hydrolysis with a chemical such as acid or alkali. Specifically, sulfuric acid, hydrochloric acid, nitric acid and other acidic or sodium hydroxide, potassium hydroxide, ammonia, urea and other alkaline chemicals can be used directly. Depending on the case, the sugar can be obtained by treating at room temperature with the above chemicals or by performing heat treatment at a high temperature for about 10 minutes to 1 hour. In addition to the above treatment conditions, there is no limitation on the treatment conditions as long as it is possible to obtain a saccharide by using conditions such as acid, alkaline chemicals, high temperature, and high pressure.

  As an example of the above treatment, concentrated sulfuric acid 70%, a temperature of about 20 to 100 ° C., and a reaction time of about 5 minutes to 1 hour can be mentioned. This treatment method is also a condition for recovering sugar from cellulose and hemicellulose to the maximum extent.

  By the hydrolysis treatment, cellulose and hemicellulose in the fiber contained in the oil palm trunk are hydrolyzed to produce pentose and hexose. Next, the hydrolysis reaction product is subjected to solid-liquid separation. Filtration, centrifugation, etc. can be used for the method of solid-liquid separation. It is preferable to use filtration with low energy consumption. The filtrate obtained by solid-liquid separation includes glucose, xylose, arabinose, galactose, mannose and the like, which are sugars derived from cellulose and hemicellulose.

  The sugar solution obtained by hydrolyzing the fiber of this oil palm trunk is added to the above-mentioned sap or separately from each other, and a nutrient source containing nitrogen and phosphorus and the microorganisms described later are added to the appropriate temperature and pH. The microorganism can be cultured under conditions such as alcohol fermentation to produce ethanol, or lactic acid fermentation to produce lactic acid.

  Cellulase, hemicellulase, and both fermentation microorganisms described later can be added directly to the fiber suspension of the oil palm trunk, and enzymatic hydrolysis and fermentation can be performed in parallel.

  The sap obtained from the oil palm trunk and the sugar solution obtained by hydrolysis of the fiber can be adjusted in sugar concentration by adjusting the water content in order to obtain the best form. Specifically, the sugar content is preferably in the range of 5% by weight to 30% by weight, but any concentration range may be used as long as fermentation by microorganisms is performed even at a sugar concentration lower or higher.

  The sap that is a composition from the oil palm trunk and the sugar solution obtained from fiber hydrolysis may be adjusted in pH to obtain the best form. Although it does not restrict | limit as long as it exists in the range in which the microorganisms mentioned later can grow as pH, For example, it adjusts to 4-7.5, Preferably 5-7.0. For the adjustment of the pH, acids such as hydrochloric acid, sulfuric acid, acetic acid and citric acid which are usually used as pH adjusting agents, alkalis such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium hydrogen carbonate and ammonia, or Any of salts such as Tris hydrochloride and hydrogen phosphate can be used.

  If necessary, nitrogen salts such as ammonium sulfate and ammonium hydrogen phosphate, culture auxiliary ingredients such as yeast extract, corn steep liquor, polypeptone, meat extract, casein hydrolyzate, soybean extract, and other optional ingredients are added to the above oil. It can also be used in combination with sap and sugar solution from palm trunk. In addition, inorganic salts such as potassium salt, sodium salt, phosphate, magnesium salt, manganese, zinc and iron are added as necessary. Moreover, what is necessary is just to add the nutrient required for growth, when using the microorganisms to which auxotrophy is provided. If necessary, antibiotics such as penicillin, erythromycin, chloramphenicol and neomycin may be added.

  As an example of a nutritional supplement component, when adding a yeast extract, it is good to adjust to the range which becomes 0.01 to 2 weight% of yeast extract in 100 weight% of sap. If it is the range of this addition ratio, fermentation of microorganisms can be accelerated | stimulated.

Next, microorganisms used during fermentation will be described.
Examples of microorganisms used in ethanol fermentation include Saccharomyces yeasts and Zymomonas bacteria. Examples of microorganisms used in lactic acid fermentation include Lactobacillus bacteria and Streptococcus bacteria. It is not limited to these microorganisms, and any microorganism can be used as long as it can ferment ethanol and lactic acid from compositions such as sap and sugar solution collected and collected from the oil palm trunk. For example, microorganisms such as yeast and lactic acid bacteria that have been genetically modified may be used, and ethanol and lactic acid can be efficiently produced by using these microorganisms. Moreover, you may use the microorganisms which produce hydrolase, such as a cellulase, for example, a Bacillus bacterium or a Clostridium bacterium, etc.

  As temperature at the time of fermenting, the culture temperature of 25 to 45 degreeC vicinity is preferable, and microorganisms can be effectively fermented in this temperature range. Depending on the type of microorganism, it may be cultured and fermented in a low temperature range of 25 ° C. or lower or in a high temperature range of 40 ° C. or higher. As other culture conditions, it is preferable to culture under anaerobic conditions in which oxygen concentration is limited or aerobic conditions depending on the microorganism to be used.

  According to the method for producing ethanol of the present invention, ethanol can be stably produced at a high yield and at a low cost using a composition other than the bark derived from oil palm trunk as a raw material. As the composition, any of sap, free sugar obtained by separation or separation and extraction from sap, fiber residue including vascular bundles after collecting sap, or a mixture thereof can be used. Ethanol obtained by this production method may be mixed with gasoline as an alternative energy for petroleum, and can be used not only as a gasoline additive such as ethyl tertiary butyl ether, but also as a chemical raw material such as ethylene. As additives, it can be used for the production of beer, distilled liquor and other alcoholic beverages, soft drinks, pickles, soy sauce, etc., and for the production of pharmaceuticals and quasi drugs.

  According to the method for producing lactic acid of the present invention, lactic acid can be stably produced at a high yield and at a low cost using a composition derived from an oil palm trunk as a raw material. Lactic acid obtained by this method is not only used as a raw material for polylactic acid, a biodegradable plastic, but also as a food additive, for producing beer, distilled liquor and other alcoholic beverages, soft drinks, pickles, soy sauce, etc. It can also be used for the manufacture of quasi-drugs and quasi-drugs.

  In any of the above manufacturing methods, not only can we produce ethanol and lactic acid at high yield and low cost, but also increase the resource value for the felled oil palm trunk, using the harvested oil palm trunk, which has been treated only as waste, as a raw material. It is possible to establish a sustainable oil palm industry and reduce environmental impact.

Furthermore, an Example is given and this invention is demonstrated in detail. In addition, an Example does not restrict | limit the scope of the present invention at all.
An oil palm trunk having a diameter of 32 to 33 cm after felling is sliced into a disk shape with a thickness of 6.8 to 7.0 cm, and from the center toward the bark 14, the center region 11, the intermediate region 12, and the outer region 13 Cut into 3 equal parts at 5 cm intervals. Except for the outermost bark 14, the outer region 13, the intermediate region 12, and the central region 11 were each roughly pulverized and further finely pulverized by a rotary pulverizer to obtain an oil palm trunk pulverized product. The pulverized oil palm trunk for each region was squeezed and filtered using a glass filter, and the sap was collected. The amount of sap collected by filtration was about 140 cm ³ from the central region 11, about 80 cm ³ from the middle region 12, and about 40 cm ³ from the outer region 13.

  The moisture contained in each region of the oil palm trunk 10 was measured. Approximately 3 to 5 g of the finely pulverized oil palm trunk pulverized product was accurately weighed and heated to 100 ° C. for 24 hours to dry. Moisture weight was calculated by accurately weighing the dried oil palm trunk ground product and subtracting it from the weight of the oil palm trunk ground product before heat drying. As a result, the moisture content is 83% with respect to the weight of the central region 11, 75% with respect to the weight of the intermediate region 12, and 68% with respect to the outer region 13, and the oil palm trunk 10 has a large amount of moisture. It was found that it was included.

  After collecting the sap, in order to examine the sugar composition of the fiber part including the vascular bundle remaining on the glass filter, the fiber was washed with distilled water, and then 72% sulfuric acid at 30 ° C. for 1 hour and 3% sulfuric acid at 121 ° C. for 1 hour. The hydrolysis process was performed by the process of.

The sap of each part and the sugar composition and sugar content of the fiber part were measured by high performance liquid chromatography using a pulsed electrochemical detector (HPAE-PED) method. As analysis conditions, a Dionex PA-1 column was used, and a 2% aqueous sodium hydroxide solution (0.6 cm ³ / min, 28 ° C.) was used as an eluent.

Table 1 is a chart showing the free sugar composition and content of sap obtained from each region of the felled oil palm trunk. As free sugars of sap obtained from each region of oil palm trunk, arabinose, galactose, glucose, xylitol, rhamnose, mannose and the like were included. In the central region 11, 98 g / 10 ³ cm ^{3 of} free sugar was obtained as a whole. The amount of each component of the free sugar (composition ratio (%)) is the highest at 86.9% for glucose, hereafter 6.6% for arabinose, 4.2% for mannose, 0.9% for galactose, and xylose 0.7% and rhamnose were 0.4%.

In the middle region 12, 60.5 g / 10 ³ cm ^{3 of} free sugar was obtained as a whole, and the amount of each component was the highest at 86.2% for glucose, and 5.1% for mannose and 5% for arabinose. Xylose was 1.4%, galactose was 1.3%, and rhamnose was 0.8%.

In the outer region 13, 20.5 / 10 ³ cm ^{3 of} free sugar was obtained as a whole, and the amount of each component was the highest at 65.7% for glucose, hereafter 10.5% for mannose, and 9.7 for arabinose. 3%, xylose 7.2%, galactose 4.8% and rhamnose 2.5%.

From the above results, free sugars sap obtained from each area of oil palm stem, the central region 11, an intermediate region 12 and outer region 13, ^{respectively, 98g / 10 3 cm 3,} 60.5g / 10 3 cm 3 20 g / 10 ³ cm ³ , indicating that the central region 11 is the largest and the outer region is the smallest. It was found that the free sugar had the largest amount of glucose in each region of the oil palm trunk and had a composition of about 66% or more, and the central region 11 and the intermediate region 12 contained 86% or more.

Table 2 is a table showing the composition and content of constituent sugars contained in each region of the oil palm trunk fiber after the extraction of free sugars, and arabinose, galactose, glucose, and xylose are included as sugars. I understand. In the central region 11, 0.85 g of free sugar as a whole was obtained per 1 g of dry weight of stem fiber. The amount of each component of the free sugar was 0.61 g for glucose, and 0.02 g for arabinose, 0.02 g for galactose, and 0.19 g for xylose.
In the middle region 12, 1.04 g of sugar is obtained per 1 g of dry weight of stem fiber, and the amount of each component of sugar is highest at 0.76 g of glucose, hereinafter 0.23 g of xylose and 0.03 g of arabinose. The galactose was 0.02 g.
In the outer region 13, 0.97 g of sugar is obtained per 1 g of dry weight of the stem fiber, and the amount of each component of sugar is 0.75 g of glucose, hereinafter 0.20 g of xylose, arabinose and galactose, Each was 0.01 g.

  From these results, the fiber obtained from the trunk of the felled oil palm trunk is free sugar of about 0.85 to 1.04 g per 1 g of dry weight of the trunk fiber in each part of the central region 11, the intermediate region 12 and the outer region 13. In all cases, glucose was the main component.

Next, the fiber part after obtaining the sap was washed with distilled water, and then hydrolyzed with an enzyme.
First, 20 cm ³ of 50 mM acetate buffer was added to 1.4 g of fiber to form a suspension. To this suspension, 20 units of cellulase (Novozyme) derived from the filamentous fungus Trichoderma reesei were added, and kept at 50 ° C. for 3 days for enzymatic hydrolysis. The reaction solution obtained by enzymatic hydrolysis was filtered to remove insoluble residues, and filtered to obtain a transparent sugar solution. This sugar solution contained glucose. The glucose concentration of the sugar solution is measured using a test kit (glucose CII, manufactured by Wako Pure Chemical Industries, Ltd.) and converted to the weight of oil palm trunk fiber, 0.2 g of glucose per g of oil palm trunk fiber is obtained. I understood. In the case where the above enzyme was not added, no separation of glucose was observed.

Ethanol fermentation by the microorganisms of Example 1 was performed using the sap collected from the central region 11 of the felled oil palm trunk 10.
Specifically, it is adjusted by adding distilled water so that the glucose concentration in the sap is 55 g / 10 ³ cm ^3, and 0.5% by weight of yeast extract and 0.2% by weight of ammonium sulfate are added to this sugar solution, After adjusting the pH to 6.0, filter sterilization was performed, yeast (alcoholic beverage research institute, Saccharomyces cerevisiae association No. 7) was inoculated, and fermentation was performed at 30 ° C. for 24 hours under static conditions. . After the cultivation, the ethanol concentration accumulated in the culture solution was measured using gas chromatography (manufactured by Shimadzu Corporation, model BC-2014).

(Comparative Example 1)
Next, Comparative Example 1 with respect to Example 1 will be described.
In order to examine the presence or absence of fermentation inhibition to yeast of components contained in sap, a glucose reagent (manufactured by Wako Pure Chemical, 041-00595, reagent special grade) was used, and the concentration was adjusted to 60 g / 10 ³ cm ³ with water The same yeast extract and ammonium sulfate as in Example 1 were added and sterilized by filtration to give a medium. In the same manner as in Example 1, yeast was inoculated and ethanol fermentation was performed.

Unlike Example 1, ethanol fermentation by microorganisms was performed using a raw material obtained by mixing sap prepared from the central region 11 of the felled oil palm trunk 10 and an enzyme hydrolyzate of fibers.
Here, the enzyme degradation product of the fiber was dried and concentrated overnight at 50 ° C., dissolved in the sap containing the nitrogen source obtained previously, sterilized by filter filtration, and then subjected to an ethanol fermentation test. Other conditions are the same as those in the first embodiment.

The results of Examples 1 and 2 and Comparative Example 1 will be described.
FIG. 2 is a graph showing the amount of residual glucose and the amount of ethanol produced with respect to the fermentation times of Examples 1 and 2 and Comparative Example 1. In the figure, the horizontal axis is fermentation time (hours), the left vertical axis is glucose remaining amount (g / 10 ³ cm ³ ), and the right vertical axis is ethanol production (g / 10 ³ cm ³ ). In the figure, white circles (◯), white triangles (Δ), and white squares (□) plots show the residual amounts of glucose in the culture solutions in Example 1, Example 2, and Comparative Example 1, respectively, and black circles (●). The black triangle (（) and black square (■) plots show the amount of ethanol produced in the culture solution in Example 1, Example 2, and Comparative Example 1, respectively.

As is apparent from FIG. 2, in ethanol fermentation using the sap of Example 1, most of glucose was consumed after about 12 hours of culture, and 30 g / 10 of ethanol was contained in the culture solution after 24 hours. Accumulated at a concentration of ³ cm ³ . This value corresponds to 107% of the theoretical yield of ethanol calculated from the glucose concentration, and it is considered that sugars other than glucose such as mannose and galactose contained in the sap are also converted to ethanol. The ethanol production efficiency per hour of ethanol accumulated after 24 hours was also 1.25 g / 10 ³ cm ³ . Since these numerical values are equivalent to the fermentation test of Comparative Example 1, it was found that in Example 1, ethanol fermentation was performed without any inhibition.

As apparent from FIG. 2, in the fermentation using the raw material in which the sap of Example 2 and the enzyme hydrolyzate of fiber were mixed, the glucose concentration at the start of the fermentation was 65 g / 10 ³ cm ³ and within 24 hours. Glucose was consumed, ethanol production was completed, and 33 g / 10 ³ cm ³ ethanol was produced in the culture solution. This corresponds to almost 100% of the theoretical yield of ethanol production calculated from the glucose concentration, and the ethanol production rate is as high as about 1.3 g / 10 ³ cm ³ per hour, indicating that ethanol can be produced efficiently. It was.

Using the same sap used for ethanol fermentation in Example 1, lactic acid fermentation with microorganisms was performed. The sap collected from the central region 11 was adjusted by adding distilled water so that the glucose concentration in the sap was 55 g / 10 ³ cm ³ . To this sugar solution containing sap, 0.5% by weight of yeast extract and 0.2% by weight of meat extract were added, pH was adjusted to 7.0, sterilization and filtration were performed, and lactic acid bacteria (American Type Culture) were added. Collection Lactobacillus lactis ATCC 19435 strain) was inoculated and kept at 30 ° C., so-called stationary culture was performed for 48 hours. After lactic acid fermentation, the concentration of lactic acid accumulated in the culture solution was measured using a high performance liquid chromatography organic acid analysis system (Prominence, manufactured by Shimadzu Corporation) using a post-column pH buffered conductivity detection method.

(Comparative Example 2)
Next, Comparative Example 2 with respect to Example 3 will be described.
In order to examine the presence or absence of fermentation inhibition to yeast of components contained in sap, a glucose reagent (manufactured by Wako Pure Chemical, 041-00595, reagent special grade) was used, and the concentration was adjusted to 60 g / 10 ³ cm ³ with water. The same yeast extract and meat extract as in Example 3 were added and sterilized by filtration to give a medium. In the same manner as in Example 3, lactic acid bacteria were inoculated and lactic acid fermentation was performed.

Lactic acid fermentation was performed in the same manner as in Example 3 except that a raw material obtained by mixing the sap prepared from the central region 11 of the felled oil palm trunk 10 and the enzyme hydrolyzate of fibers was used.
Here, the enzyme degradation product of the fiber was dried and concentrated overnight at 50 ° C., dissolved in the sap containing the nitrogen source obtained earlier, and used after being filtered through a filter.

The results of Examples 3 and 4 and Comparative Example 2 will be described.
FIG. 3 is a graph showing the remaining amount of glucose and the amount of lactic acid produced with respect to the fermentation times of Examples 3 and 4 and Comparative Example 2. The vertical axis represents the fermentation time (hours), the left vertical axis represents the remaining amount of glucose (g / 10 ³ cm ³ ), and the right vertical axis represents the amount of lactic acid produced (g / 10 ³ cm ³ ). In the figure, white circles (◯), white triangles (Δ), and white squares (□) plots indicate the amount of glucose remaining in the culture solutions in Example 3, Example 4, and Comparative Example 2, respectively, and black circles (●). The black triangle (（) and black square (■) plots show the amount of lactic acid produced that accumulates in the culture solution in Example 3, Example 4, and Comparative Example 2, respectively.

In lactic acid fermentation using the sap of Example 3, most of glucose was consumed after 48 hours of culture, and lactic acid accumulated in the culture solution at a concentration of 50 g / 10 ³ cm ³ . The lactic acid production rate was also about 1.04 g / 10 ³ cm ³ per hour. These results were almost equivalent to the fermentation test in the glucose medium of Comparative Example 2 which is a control test.

Example 4 is a lactic acid fermentation in the case where the sap of Example 3 was further mixed with an enzyme degradation product of fiber, and the glucose concentration at the start of fermentation was 65 g / 10 ³ cm ³ . After 48 hours of culture, glucose was consumed and production of lactic acid was completed, and lactic acid accumulated in the culture solution at a concentration of 58 g / 10 ³ cm ³ . The lactic acid production rate was about 1.2 g / 10 ³ cm ³ per hour, which was equivalent to the case of lactic acid fermentation of Comparative Example 2.

In order to separate and extract free sugars from the sap, the sugars detected by sugar analysis using high performance liquid chromatography described in Example 1 were separated.
FIG. 4 is a diagram showing a separation chromatogram of free sugars contained in the sap of Example 5. In the figure, the horizontal axis represents the elution time (minutes), and the vertical axis represents the signal intensity (mA). As can be seen from FIG. 4, glucose 15, which is a fraction showing a peak at an elution time of about 32 to 44 minutes, was extracted from the free sugar. Similarly to glucose 15, fractions recognized as other peaks were also collected. The collected glucose solution or a solution comprising other free sugars collected in the same manner was freeze-dried. Thus, it was found that the free sugar in the sap can be easily separated and recovered by using appropriate chromatography.

Using only the sap obtained in Example 1, ethanol fermentation was performed using the same yeast as in Example 1. The sap collected from the central region 11 (glucose concentration is 55 g / 10 ³ cm ³ ) is not added with the nitrogen source added in Example 2, and the pH is not adjusted. The same yeast as in Example 1 was inoculated, and ethanol fermentation was performed under the same culture conditions (30 ° C., 24 hours).

  In Example 6, the accumulation of ethanol was confirmed at a yield of 100% in substantially the same manner as the result obtained in Example 1 from the culture medium.

Using only the sap obtained in Example 1, lactic acid fermentation with lactic acid bacteria was performed. Without adding the nitrogen source added in Example 3 to the sap collected from the central region 11 (glucose concentration is 55 g / 10 ³ cm ³ ), without adjusting the pH, filter sterilization and filtration are performed directly, The same microorganism as in Example 4 was inoculated, and lactic acid fermentation was performed under the same culture conditions (30 ° C., 48 hours).

  In Example 7, the accumulation of lactic acid was confirmed at a yield of 100% in substantially the same manner as the result obtained in Example 3 from the culture solution.

  From the results of Examples 6 and 7, it was found that by using only the sap and the microbial species used in Examples 1 and 3, ethanol fermentation or lactic acid fermentation can be easily and efficiently performed.

  According to the said Example, it confirmed that ethanol or lactic acid could be manufactured cheaply and easily using compositions, such as the felling oil palm trunk | band or its sap which are discarded in large quantities.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the invention described in the claims. The raw material collected from the oil palm trunk can be subjected to various treatments, and the medium used for ethanol fermentation and lactic acid fermentation and the yeast used for these fermentation are appropriately selected according to the raw material obtained from the oil palm trunk and its shape Needless to say, they are also included within the scope of the present invention.

  The present invention is the development of a technique for producing ethanol for fuel or lactic acid for bioplastics at low cost and easily using the central part of palm trunk, which is mostly discarded, and reduces fossil resource consumption and the earth. It contributes to the development and development of new biomass industries aimed at solving environmental problems such as global warming. In addition, it is thought to contribute greatly to further efficiency, higher profitability and sustainable development of the palm oil industry centered on Southeast Asia.

(A) is a perspective view of the ring | wheel which cut | disconnected the oil palm trunk which extract | collects sap in the direction perpendicular | vertical to an axial direction, (B) is sectional drawing in alignment with the XX direction of (A). It is a graph which shows the residual amount of glucose with respect to the fermentation time of Example 1 and 2 and the comparative example 1, and the production amount of ethanol. It is a graph which shows the residual amount of glucose with respect to the fermentation time of Example 3 and 4 and the comparative example 2, and the production amount of lactic acid. It is a figure which shows the separation chromatogram of the free sugar contained in the sap of Example 5.

Explanation of symbols

10: Oil palm trunk 11: Central region 12: Intermediate region 13: Outer region 14: Bark 15: Glucose peak

In order to achieve the first object, the present invention is a method for producing ethanol from an oil palm trunk, (1) a step of removing bark from the oil palm trunk;
(2) A step of collecting sap from the oil palm trunk from which the bark has been removed, (3) a step of hydrolyzing the fiber of the oil palm trunk after collecting the sap with an enzyme, and (4) the above step (2). And the step of fermenting the hydrolyzate obtained in the above step (3) with a microorganism .
In particular, sap collected from oil palm trunk, or its sap, and monosaccharide or oligosaccharide obtained by hydrolyzing fiber of oil palm trunk after collecting sap are mixed, and the mixture is fermented with microorganisms And ethanol is produced.
In the above configuration, preferably, a free sugar obtained by separation and extraction from the composition or sap may be fermented. The microorganism is preferably one or more microorganisms selected from the group consisting of bacteria and yeast.
The ethanol of the present invention is produced using any of the above production methods.

In order to achieve the second object, the present invention is a method for producing lactic acid from an oil palm trunk, wherein (1) a step of removing the bark from the oil palm trunk, and (2) the bark is removed. A step of collecting the sap from the oil palm trunk, (3) a step of hydrolyzing the fiber of the oil palm trunk after collecting the sap with an enzyme, and (4) the sap collected in the step (2) and the step ( And 3) fermenting the hydrolyzate obtained in 3) with a microorganism.
In particular, sap collected from oil palm trunk and monosaccharide or oligosaccharide obtained by hydrolyzing oil palm trunk fiber after collecting sap are mixed, and the mixture is fermented with microorganisms to produce lactic acid It is characterized by doing.
In the above configuration, preferably, a free sugar obtained by separation and extraction from the composition or sap may be fermented. The microorganism is preferably one or more microorganisms selected from the group consisting of bacteria and yeast.
The lactic acid of the present invention is produced using any of the above production methods.

The present invention relates to a method for producing ethanol and lactic acid , and more particularly to a method for producing ethanol and lactic acid that can be produced from an oil palm trunk at a high yield and at a low cost.

In order to achieve the first object, the present invention is a method for producing ethanol from an oil palm trunk, (1) a step of removing bark from the oil palm trunk;
(2) A step of collecting sap from the oil palm trunk from which the bark has been removed, (3) a step of hydrolyzing the fiber of the oil palm trunk after collecting the sap with an enzyme, and (4) the above step (2). And the step of fermenting the hydrolyzate obtained in the above step (3) with a microorganism.
In particular, sap collected from oil palm trunk, or its sap, and monosaccharide or oligosaccharide obtained by hydrolyzing fiber of oil palm trunk after collecting sap are mixed, and the mixture is fermented with microorganisms And ethanol is produced.
In the said structure, you may ferment the free sugar obtained by separating and extracting from a composition or a sap. The microorganism is preferably one or more microorganisms selected from the group consisting of bacteria and yeast .

In order to achieve the second object, the present invention is a method for producing lactic acid from an oil palm trunk, wherein (1) a step of removing the bark from the oil palm trunk, and (2) the bark is removed. A step of collecting the sap from the oil palm trunk, (3) a step of hydrolyzing the fiber of the oil palm trunk after collecting the sap with an enzyme, and (4) the sap collected in the step (2) and the step ( And 3) fermenting the hydrolyzate obtained in 3) with a microorganism.
In particular, sap collected from oil palm trunk and monosaccharide or oligosaccharide obtained by hydrolyzing oil palm trunk fiber after collecting sap are mixed, and the mixture is fermented with microorganisms to produce lactic acid It is characterized by doing.
In the said structure, you may ferment the free sugar obtained by separating and extracting from a composition or a sap. The microorganism is preferably one or more microorganisms selected from the group consisting of bacteria and yeast .

Claims (12)

  A method for producing ethanol, wherein a composition other than an oil palm stem-derived bark is fermented with microorganisms to obtain ethanol.   The method for producing ethanol according to claim 1, wherein the composition comprises sap.   Sap collected from oil palm trunk and monosaccharide or oligosaccharide obtained by hydrolyzing fiber of oil palm trunk after collecting sap are mixed, and the mixture is fermented with microorganisms to obtain ethanol A method for producing ethanol, comprising:   The method for producing ethanol according to claim 1 or 3, wherein a free sugar obtained by separation from the composition or sap is fermented.   The method for producing ethanol according to claim 1 or 3, wherein the microorganism is one or more microorganisms selected from the group consisting of bacteria and yeast.   Ethanol produced by the production method according to any one of claims 1 to 5.   A method for producing lactic acid, comprising fermenting a composition other than bark derived from oil palm trunk with microorganisms to obtain lactic acid.   The method for producing lactic acid according to claim 7, wherein the composition comprises sap.   Mixing sap collected from oil palm trunk and monosaccharide or oligosaccharide obtained by hydrolyzing fiber of oil palm trunk after collecting sap, and fermenting the mixture with microorganisms to obtain lactic acid A process for producing lactic acid, characterized in that   The method for producing lactic acid according to claim 7 or 9, wherein a free sugar obtained by separation from the composition or sap is fermented.   The method for producing lactic acid according to claim 7 or 9, wherein the microorganism is one or more microorganisms selected from the group consisting of bacteria and yeast.   Lactic acid produced by the production method according to any one of claims 7 to 11.

Images