JPH0731465A - Biological treatment method for wood waste - Google Patents

Abstract

(57) [Summary] [Purpose] By biodegrading lignins, which have been extremely difficult to decompose by microorganisms in the past, the fiber is economically, rapidly, and efficiently decomposed into monosaccharides. Also provided are biological treatment methods that can also produce. [Composition] A lignin decomposing step of decomposing lignin into hydrogen and lower carbon compounds by microorganisms,
Then, when biologically treating with a cellulose saccharification step of decomposing the cellulosic material into monosaccharides, an intestinal microbial community of termites anaerobically accumulated in the presence of at least C _x cellulase is used as the microorganism. Also in the cellulose saccharification step, it is preferable to use the above-mentioned termite intestinal microbial community.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological treatment method for woody wastes, and in particular lignins, fibers and / or carbohydrates as its constituent elements such as agricultural wastes and / or forestry wastes. Lignin is decomposed by effectively utilizing the function of microorganisms from the organic waste containing a large amount of, for example, the organic waste containing a large amount of lignin, and wood tissue (plant tissue)
The present invention relates to a biological treatment method for reducing the molecular weight of cellulosic (fibrous) from which lignin has been removed and / or dissociated into monosaccharides.

[0002]

2. Description of the Related Art Conventionally, agricultural wastes and forest wastes contain a large amount of recyclable fiber as a useful resource, and many studies have long been conducted to biotransform this fiber into a substance with high added value. It was carried out and the search for practical use was made. So-called waste cellulose derived from these organic wastes has reached an enormous amount as an unused resource existing on the earth, and if useful cellulose can be bio-converted into monosaccharides (saccharification), various useful various It can be used for multiple purposes as a fermentation basic substance for substance production.

From this point of view, "human beings living on the earth at the present time should recycle wastes to live, and virgin resources are for the survival and prosperity of offspring. The idea of "should be preserved" was established, and the recycling of waste cellulose was tried, and many efforts are still being made. However, since naturally occurring plant cellulose is strongly protected by lignin without exception, delignification and / or lignin decomposition cannot be carried out at a practical economical cost, and at the present stage, added value is It is only used as a low substance.

In order to solve this problem, that is, for leaching or decomposing lignin from waste cellulose, conventionally, an acid (hydrochloric acid) / alkali method (ammonia, sodium hydroxide) (high temperature, pressure digestion method), The blasting method and the pulverization method using a powerful crusher such as a hammer mill (which facilitates the decomposition by enzymes or microorganisms) have been studied, but both of them are efficient and economical, especially the cost. From the aspect, there is no possibility of practical application, and the recycling of waste cellulose is still an unsolved problem as "an old and always new problem". As described above, in the conventional method for recycling organic waste such as agricultural waste and forest waste, there is no technology that can be evaluated from the viewpoint of the added value of the substance produced.

[0005]

As described above, against the reality, in recent years, energy shortages and food shortages are becoming apparent on a global and global scale. There is a strong global and social demand for research and development and establishment of recycling technology of waste and recycling technology in a form that can be used by humankind while suppressing consumption as much as possible. The present invention solves such a fatal defect of the prior art, and an innovative method of recycling organic waste by a completely new idea, that is, lignin strongly bound to waste cellulose is used as a biological material. To provide an economical, fast, and highly efficient biological treatment method that not only chemically decomposes cellulose into monosaccharides but also produces hydrogen as a secondary clean energy. Is an issue.

[0006]

In order to solve the above-mentioned problems, in the present invention, a wood-based waste is decomposed by a microorganism into lignin into hydrogen and lower carbon compounds, and then a cellulosic material is simply decomposed. upon treating biologically by the decomposing cellulose saccharification step to a saccharide, as the microorganism, in which we decided to use the enteral microbial community termites that anaerobic enrichment culture at least C _x cellulase presence. In the above method, the intestinal microbial community of termites used in the lignin decomposition step is preferably used in the cellulose saccharification step.

Next, the present invention will be described in detail. In the present invention, microbial production C _x produced by Trichoderma, which is a kind of aerobic fungi, is usually used to produce the termite intestinal tract microbial community that circulates lignin and cellulose of biomass by exquisite physiological functions in nature. Cellulase (usually C ₁ cellulase is also produced at the same time) and / or commercially available C _x cellulase is added to carry out integrated culture in a specific medium to prepare a mixed culture solution of protozoa and bacteria that coexist in the termite intestinal tract system. It is necessary for the lignin decomposition tank to which the treatment liquid is added by crushing the organic waste of wood-based organic waste in advance and adding water to form a slurry, and the cellulose saccharification tank that is the next treatment step. Depending on the condition, it continuously and / or intermittently injects to biodegrade lignin rapidly and efficiently, and saccharifies lignin-unbonded cellulose and stabilizes it at the same time. It is those allowed to produce the original.

Further, in the present invention, in utilizing the function of the termite intestinal tract microorganism, rather than relying on the specific function of the specific pure bacterium isolated and identified, a mutual symbiotic relationship is established in the intestinal tract system. In this way, a series of food chains are constructed to decompose and assimilate lignin and cellulose, and a mixed culture system of a microbial community that circulates these without resistance in a natural ecosystem is used. Furthermore, in the lignin degrading tank according to the present invention, as a result of lignin in wood being decomposed by the synergistic action of protozoa and bacteria originating in an integrated culture mixture of intestinal microbial community, lignin and cellulose A part of is decomposed into hydrogen, carbon dioxide and lower fatty acids.

Therefore, the equilibrium concentration of hydrogen increases in the liquid phase of the lignin decomposition tank, and the hydrogen partial pressure in the gas phase part also increases. Hydrogen fermentation, which proceeds in a lignin decomposing tank, is an absorption ergon reaction in which the standard free energy of the biological reaction has a positive value, and this biological reaction is inherently difficult to proceed in the positive direction. Below is shown the biological reaction formula when the butyric acid substrate is hydrogen fermented by mixed culture of intestinal microorganisms,
As can be understood from now on, the standard free energy of this biological reaction is +48.1 Kj · reaction ⁻¹ . Hydrogen fermentation of butyric acid substrate (Ergon absorption reaction) CH ₃ (CH ₂ ) ₂ COO ⁻ + 2H ₂ O → 2CH ₃ CO
O ^{- +} H ^{+ +} 2H ₂

The hydrogen produced as a result of the biological reaction is
Not only the reaction is an absorption ergon reaction, but when it is accumulated above the concentration in the liquid in the tank and in the gas phase of the tank, it becomes a biological poison, and hydrogen, which is one of the main objects of the present invention, is hydrogen. The fermentation itself will stop. Therefore, in order to proceed the decomposition of lignin and the hydrogen fermentation of fibrous material dissociated from lignin without delay, the lignin decomposition tank is under reduced pressure conditions, and the raw material slurry liquid is subjected to reduced pressure fermentation to obtain hydrogen in the liquid phase. It is preferable that the equilibrium concentration can be lowered and the hydrogen partial pressure in the gas phase part can be forcibly reduced, and the above-mentioned obstacle can be eliminated.

Further, in the present invention, as another method for smoothly proceeding hydrogen fermentation, hydrogen generated by hydrogen fermentation is forced to be taken out of the biological reaction system by passing it through a gas separation membrane. Therefore, the above-mentioned problems can be solved, and the separated and concentrated hydrogen gas can be used as a clean energy for various purposes, which is preferable.
Regarding the biodegradation of lignin, effective use of wood-based substances,
Alternatively, there have been excellent researches by many researchers for the purpose of treatment / disposal for a long time, and lignin-degrading microorganisms, their enzyme systems and degradation models (metabolic models) have been published at this time, but no clear conclusions have been reached. Absent.

According to the research of the pioneers so far, it is a white rot fungus belonging to Basidiomycetes that decomposes lignin relatively well, and recently, the lignin decomposition of Phanerochaete chrysosporium was carried out. The mechanism is relatively well investigated. It has been confirmed that the enzymes involved in this are peroxidase and phenol oxidase, but in any case, even white-rot fungi with the highest decomposition rate require tens of days to decompose lignin. , Decomposition in a practical time range is not desirable.

Biodegradation of lignin is a secondary metabolism, requires the coexistence of oxygen with carbohydrates such as cellulose and glucose, and it is said that the degradation proceeds when nitrogen is present in a starved state. In addition to basidiomycetes, fungi such as Xylaria, Fusarium, and Chaetomium, actinomycetes, Streptomyces,
Nocardia, Pseudomona
It is said that some bacteria such as s) and Bacillus partially decompose lignin, but its decomposition mechanism has not been clarified.

On the other hand, it has been confirmed that regardless of the species, termites eat woody substances to surely decompose lignin, and the decomposed lignin is assimilated as a carbon source for termites. Is believed to be. At this stage,
It is not confirmed whether lignin is decomposed by protozoa among the termite intestinal tract microorganisms, or whether bacteria or filamentous fungi are decomposed, but a mixed culture system of these symbiotic microorganisms is sure, And it decomposes lignin at high speed (the lignin-degrading enzyme has not been elucidated and has not been decomposed and purified).

What should be noted here is that the lignin decomposition rate and the decomposition rate of the termite intestinal microbial mixed culture system are far superior to those of basidiomycetes, and the retention time of lignin in the termite intestinal system is remarkable. It has been confirmed by many researchers that the lignin decomposition rate of each termite is as follows, although the (digestion time) is about 24 hours at the longest. Lignin Degradation Rate of Various Termites Carotermes flavicolli
s) 1.7 to 35.6% Heterotermes indicola
14.5-50.5% Reticulitermes
santonensis) 70-80.3% Nasutitermes ephratae
42.5-51.5%

The present invention focuses on the exquisite and excellent lignin and carbohydrate degrading function of termite intestinal microorganisms in this reality, and lignin the ecological system of mutual interest of termite intestinal microorganisms to woody organic waste. By reproducing under the supply of C ₁ and C _x cellulase in the circulation outside the body called a decomposition tank, the above substances can be decomposed efficiently and at high speed, and at the same time, bioconversion into clean energy called hydrogen for utilization It has a feature.

Furthermore, in the lignin decomposing tank, the woody organic waste is solubilized by the action of the enzyme laccase, and the lignin leached in the liquid is partially hydrogenated and polysaccharides due to the coexistence with organic carbon compounds such as carbohydrates. It is thought that it is possible to lower the molecular weight of various derivatives (including glycogen), benzene nuclei, and phenol nuclei.
In the previous studies, it has been reported that the degradation of lignin is reduced to a low molecular weight by the oxidative degradation mechanism, but it is judged that the lignin degradation by the termite intestinal system is naturally controlled by the anaerobic degradation mechanism.

At present, there may be no research report on anaerobic decomposition of lignin, and thus, strictly speaking, the products of lignin decomposition by termite intestinal tract microorganisms in the lignin decomposition tank cannot be estimated. In the present invention, the decomposition product of this wood-based organic waste is transferred to the cellulose saccharification tank, which is the next main step, and the residual organic compound partially converted to hydrogen in the previous step is used as a target. Microorganism-producing C ₁ , C _x cellulase and / or commercially available complex cellulase, and if necessary, an added culture solution of an intestinal tract microorganism of the termite is added or injected, and a monosaccharide, which is a fermentation basic substance of various useful substances, mainly glucose. Decomposes into low molecular weight.

[0019]

Next, the function and effect of the present invention will be described. With the innovative new biological recycling process of the present invention,
Conventionally, so-called waste cellulose containing lignin, which could not be converted to a substance with high added value at all, can be partially converted to hydrogen which is clean energy,
Furthermore, it has become possible to decompose it into monosaccharides. Therefore, the present invention is a very effective method for recycling organic waste as a total process, and not only significantly contributes to the construction of a material circulation system that is macroscopically resistant to natural ecosystems, It is a method of recycling biological organic waste that also contributes to global energy problems.

The so-called lower termites such as house termites and mountain termites inhabit the intestinal system, especially in the hindgut, where various protozoans and bacteria peculiar to termites and species are inhabited. As such, termites, protozoa, and bacteria build mutual mutual symbiotic relationships. As a food habit, termites normally use natural and / or processed woody substances composed of lignin, cellulose, carbohydrates, etc. as food sources, and assimilate and / or assimilate these substances into living energy. Has gained proliferative energy. Woody substances eaten by termites, mainly lignin, cellulose, hemicellulose, etc., are mainly low-molecular-weight sugars, lower fatty acids and hydrogen, which are mainly and / or synergistically produced by the bacteria and / or synergies of the protozoa coexisting in the hindgut It is said to be decomposed into gas and carbon dioxide.

Regarding the termite intestinal microorganisms, the exquisite function as a symbiotic system has been elucidated at this stage, but very few individual microorganisms have been genus-identified. Many unexplained points remain regarding the individual roles of lignin and cellulose, which are the constituent elements of substances, in the decomposition. Since research is currently underway from the aspects of physiology, biochemistry, and enzymology, it is thought that the day when the mechanism of decomposition and metabolism of woody substances by termites is elucidated will not be so far in the future.

At present, among the microorganisms parasitizing lower termites, the main ones which are presumed to decompose lignin, cellulose, etc. and further produce hydrogen are as follows. However, there is a difference between researchers, and it proves that the research is not completed. However, this fact is scholarly, and in the present invention, since the intestinal tract microorganisms of termites are used as they are to reproduce the lignin degrading system of termites as they are, they are not an obstacle to the practice of the present invention.

Protozoa It is thought that they are mainly involved in decomposing lignin and cellulose to produce hydrogen. Terratonympha Trichonympha Prichonympha Pysonympha Holomastigotoides Dinenympha Pseudotrichonympha Spirotrichonympha

Bacteria Hydrogen producing bacteria Enterobacter Clostridium Cellulolytic bacteria Clostridium Achromobacter Ahrobacter Arthrobacter Serratia

Other Bacteria Cytrobacter Bacillus Escherichia Streptococcus Pseudomonas Stapylococcus

The bioreaction formula for producing hydrogen by using cellulose obtained by decomposing and / or leaching lignin from a woody substance as a substrate by the overall function of the mixed culture system of termite intestinal microorganisms is shown below. On the street. Hydrogen production by protozoa (C ₆ H ₁₀ O ₅ ) _n → C ₆ H ₁₂ O ₆ → CO ₂ + H ₂ + C
H ₃ COOH Hydrogen production by bacteria (C ₆ H ₁₀ O ₅ ) _n → C ₆ H ₁₂ O ₆ → CO ₂ + H ₂ + C
H ₃ (CH ₂ ) ₂ COOH Hydrogen production by the genus Clostridium (C ₆ H ₁₀ O ₅ ) _n → 4C ₆ H ₁₂ O ₆ → 2CH ₃ COO
H + 3CH ₃ (CH ₂ ) ₂ COOH + 8H ₂ + 8CO ₂

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Example 1 FIG. 1 shows an overall process diagram of the biological treatment method of the present invention.
First, the enrichment culture step will be described with reference to FIG. In FIG. 1, cellulase-producing bacteria (microorganism-producing C ₁ and C _x cellulase) 1 required for integrated culture of termite intestinal microorganisms 5 are selected and subjected to volumetric culture with a specific culture solution.

[0028] Usually, it is desirable to select Trichoderma viride and / or Trichoderma reesei, which are aerobic filamentous fungi, as a bacterium that produces a strong cellulase, but in the present invention, it is preferable. Without being limited to this, any bacterium that produces a strong cellulase can be used. However, bacteria that have been selected as cellulase, it is capable of producing at least C _x cellulase (CMC = carboxymethyl cellulase) is a prerequisite.

This enzyme acts on a non-crystalline cellulose fragment whose crystallinity has been destroyed by C ₁ cellulase to give a cellooligosaccharide such as cellobiose or cellotriose.
First, it has the function of disassembling. Furthermore, C ₁ to as an essential condition for selecting the cellulase producing strain, cellulases bacteria selected to produce not only C _x cellulase acts on at least cellulose, destroying its crystalline
It must be a bacterium that also produces cellulase.

In the present invention, the cellulase-producing bacterium 1 is Trichoderma viridii-ATCC 8678 (Trichoderm).
a viride ATCC8678 = Trichoderma lignorum NRRL1762)
, ATCC medium 336 POTATO DEX
30 g / l of commercially available cellulose powder in TROSE medium
(Excluding agar) The added medium was used as a liquid medium, the culture temperature was set to 25 ° C., the culture period was set to 3 to 5 days, and the culture was expanded to perform slow aeration. Next, the termites, especially the termites that have excellent lignin degrading power (about 200 lower termites in which the intestinal system is symbiotic with protozoa and bacteria are washed with sterilized saline solution several times, Are thoroughly ground and the termite intestinal tract microbial community 5 is taken out of the termite body.

Usually, various protozoa and bacteria inhabit the intestinal tract system of lower termites while maintaining a mutualistic relationship, and in these mixed culture systems, specific enzymes ( Mainly C _x cellulase) and the supply of trace elements required for growth and proliferation, termites and microorganisms doubly symbiotic with each other, and decompose them using natural lignin, natural cellulose and carbohydrates as organic carbon sources. It is known that assimilates and produces saccharides (such as glycogen) and lower fatty acids (such as butyric acid and acetic acid) as metabolic products, and simultaneously produces hydrogen gas, methane gas and carbon dioxide gas. The termite intestinal tract microbial community 5 treated by the above method is put into an integrated culture tank 6 maintained under absolutely anaerobic conditions, and the specific culture solution 7 shown in Table 1 is put into the integrated culture tank.

[0032]

[Table 1]

Further, a mixed culture solution of cellulase-producing bacterium 1 cultivated in the above-mentioned mixed culture tank (microbe-produced C _x cellulase ... Normally C ₁ is also produced) is injected into the injection tube while containing the cells. 1 to 1000 to 1/10000 per volume of the integrated culture tank 6 through 3 or a commercially available cellulase (composite cellulase) 2 is added to the integrated culture tank 6 through the input pipe 4 at an addition concentration of 1000 to 2000 mg.
1 / l, and batch culture is performed at 30 ° C. for 5 days to accumulate the termite intestinal tract microbial community 5. In this culture, the microorganism-produced C _x cellulase and the commercially available C _x may be added either alone or in combination.

Next, biological lignin decomposition of an organic waste, which is a central part of the present invention, decomposition of cellulose, and hydrogen fermentation in a lignin decomposition step will be described with reference to FIG. Although various kinds of organic wastes to be the subject of the present invention are conceivable, in the present description, it is assumed that general cedar is used as a tree species, and lignin and cellulose contained in sawdust generated in the process of lumbering cedar are used. The decomposition of will be described. First, cedar sawdust (hereinafter abbreviated as sawdust) 10 is put into a slurry tank 11. Since the sawdust 10 has already been roughly crushed, tap water 12 is used as dilution water from the outside.
Is added, and the concentration is adjusted so that the total solid matter concentration of sawdust is about 4%.

This slurry-like sawdust is continuously and / or intermittently introduced into the lignin decomposition tank 13 maintained under anaerobic conditions. On the other hand, in the lignin decomposing tank 13, the culture solution 14 of the termite intestinal tract microbial community shown in Table 1 above is used.
Was continuously and / or intermittently injected so as to be 5% with respect to the slurry-like sawdust (50 ml / liter slurry-like sawdust / day in the example), and was further cultivated in concentrated culture tank 6 The intestinal microbial community culture solution is continuously and / or intermittently injected via the injection tube 8 at a supply rate of about 10 ml / liter tank volume / day.

It is desirable that the effective volume of the lignin decomposition tank 13 is usually set so that the residence time of the slurry sawdust is about 5 days. Therefore, the supply rate of the slurry sawdust to the tank 13 for this volume is 1 liter / day. Becomes The slurry sawdust 10, the accumulated culture liquid of the termite intestinal tract microorganisms and the culture liquid 14 are fermented at a fermentation temperature of 23 to 26 in the lignin decomposition tank 13.
When anaerobic fermentation was carried out under a temperature of ℃ under slow stirring, the major components of sawdust, such as lignin, cellulose and hemicellulose, were lignined by the synergistic action of various protozoa and bacteria that are termite intestinal microorganisms. Is decomposed into low-molecular compounds and at the same time partially converted to hydrogen, and the cellulose strongly protected by lignin is released from this constraint and partially converted to hydrogen.

As described above, since lignin and cellulose, which are the main components of sawdust, are partially decomposed to hydrogen, the fermentation liquid and the gas phase portion in the lignin decomposition tank 13 are filled with hydrogen gas, The equilibrium concentration of hydrogen in the liquid phase increases and the hydrogen partial pressure in the gas phase increases. Hydrogen inherently has a biotoxic effect, and when the concentration in the liquid phase exceeds a certain limit, the growth and activity of hydrogen-producing bacteria in the lignin decomposing tank 13 are inhibited, and hydrogen fermentation is stopped. Further, the hydrogen-producing reaction by a specific microorganism, that is, the biological reaction of lignin and cellulose decomposition is the absorption ergon reaction, and this reaction is difficult to proceed in the positive direction so that the standard free energy has a positive value.

Therefore, if hydrogen fermentation is continued under these conditions, as described above, a biological succession reaction is induced by the allotrophic bacteria and autotrophic bacteria coexisting in the mixed culture system, and the ergon is generated. The reaction tends to be strong, resulting in the loss of the original purpose of hydrogen fermentation. In order to eliminate this fatal defect, it is necessary to strip hydrogen accumulated in the liquid phase or gas phase of the lignin decomposition tank outside the reaction system by any means or method. This problem is solved by operating the tank 13 under a reduced pressure condition and / or by passing the generated gas through the gas separation membrane and removing the hydrogen gas out of the reaction system.

That is, as a first means, it is required that the lignin decomposing tank is fermented under reduced pressure by a conventional vacuum decomposing method. By this means, the decompression degree of the lignin decomposing tank is usually in the range of -300 to 4000 mmAq. By considering and maintaining the above, hydrogen fermentation proceeds smoothly in the positive direction. As the next means, the gas generated from the lignin decomposition tank 13 is guided to the gas decomposition film 17 and is forcibly separated into hydrogen 16 and concentrated carbon dioxide gas 18 by suction under a reduced pressure condition by a blower, and the hydrogen gas 16 is It is transferred to a use point as clean energy and used as an energy substance, and the concentrated carbon dioxide gas 18 is separately transferred and discarded, or is effectively used as a basic substance for producing a valuable substance.

Hydrogen gas has a very small particle size as a gas molecule, and hydrogen can be easily separated from a mixed gas with other gases with a high purity of about 99%. Therefore, for example, petroleum refining industry, chemical industry, etc. Has already been put to practical use in the production process. In the case where the generated gas of hydrogen fermentation of the sawdust 10 is a mixed gas of hydrogen gas and carbon dioxide gas as in the present invention, hydrogen separation by the gas separation membrane is relatively easy,
Usually, 99% high purity hydrogen gas can be separated at a pressure of 5 kg / cm ² or less. As commercially available separation membranes, several kinds of materials are sold as materials, but in the examples of the present invention, gas separation using aromatic polyimide as a material capable of separating hydrogen most selectively and effectively. A membrane was used.

Next, the sawdust 10 in the form of slurry in which the lignin and the cellulose have been partially decomposed in the lignin decomposition tank 13 is introduced into the cellulose saccharification tank 19, and microbiologically and / or
Alternatively, it is enzymatically decomposed into monosaccharides and used as monosaccharides 22 as fermentation basic substances for various useful substances.
Since a small amount of undecomposed lignin and other polymer substances may remain in the slurry sawdust 10 treated in the lignin decomposing tank 13, these are further highly decomposed to collect monosaccharides. In order to increase the rate, the cellulosic saccharification tank 19 contains approximately _{1 to 1 of} the termite intestinal tract microbial community culture liquid that is cultivated in the integrated culture tank 6 and contains C ₁ and C _x cellulase in a concentrated manner in the cellulose decomposition tank 19. / 50
About 0 to 1/1000 is injected through the injection pipe 9.

Further, in the cellulose saccharification tank 19,
In order to efficiently reduce the molecular weight of cellulose into monosaccharides, for example, a mixed culture solution 1 of Trichoderma which is an aerobic filamentous fungus that produces strong C ₁ and C _x cellulose is added to a cellulose saccharification tank. About 1/2 per volume of 19
About 50 to 1/500 is poured, and a commercially available composite cellulase 2 is flown into the tank 19 as required.
3 to 5% is added to each solid.

The reaction in the cellulose saccharification tank 19 is designed as an absolute anaerobic tank because not only enzymatic reactions but also biological reactions of protozoa and bacteria belonging to the category of absolutely anaerobic are carried out in parallel. As a matter of course, in order to improve the contact between the decomposed sawdust and the microorganisms and enzymes, stirring is always performed, and the carbon dioxide gas 21 generated mainly by the decomposition of cellulose is discharged to the outside through the gas discharge pipe 20. Dissipated. Since C ₁ and C _x cellulase play a major role in the reaction carried out in the cellulose saccharification tank 19, it is desirable to set the reaction temperature to 30 ° C. or higher and the reaction pH to the acidic side of 5.0 to 6.0.

Example 2 Sawdust generated from a sawmill was selected as an agricultural waste or a forest waste to be treated, that is, an organic waste. The sawdust used in the experiment was obtained by sun-drying the sawdust used to make a cedar lumber of a conifer, and was stored in a cool dark room at 3 to 5 ° C so as not to deteriorate during the experiment. As a raw material to be injected into the lignin decomposition tank, the above-mentioned stored sawdust is taken out if necessary, and tap water is added to adjust the solid concentration to 40 g / liter (4%). did. Table 2
The chemical composition (average value of 10 samples) of the slurry sawdust tested is shown in FIG.

[0045]

[Table 2] * 1 Chemical composition analysis method Lignin JIS method Lignin chemistry (basics and applications); Junzo Nakano, Yuko Kogyo Co., Ltd. Publishing Department (1979) Other chemical composition analysis methods Wood chemistry (above)
According to the method of. Wood Chemistry (above); Ueda, Yonezawa, Kondo, Kyoritsu Shuppan Co., Ltd., 1969

The chemical composition analysis was carried out according to the method described in the literature, as shown in the margins of Table 2. In the verification experiment of lignin contained in slurry sawdust and cellulose decomposition, first, the volume of the lignin decomposition tank was a cylindrical fermenter with an actual water filling volume (effective volume) of 5 liters, for comparison and for the method of the present invention. I made two,
Fermentation experiments were conducted under the conditions shown in Table 3 below.

[0047]

[Table 3]

The cellulase-producing strains and culture medium, culture conditions, and accumulation culture method (culture medium, culture conditions) of the termite intestinal microbial community in this experiment were the same as those described in Example 1.
It carried out according to the method. Next, the experimental apparatus and experimental conditions used in the cellulose saccharification step, which is the next step of the lignin decomposition tank, are shown in Table 4 below.

[0049]

[Table 4]

As the commercial cellulase added to the cellulose saccharification tank, the complex enzyme macerase manufactured by Meiji Seika was used. This complex enzyme is the Trichoderma viridi (Tricho
derma viride) mutant strain, and has strong C ₁ and C _x cellulases together as shown below. * Filter paper disintegration activity 6,800 Units / mg * Avicelase activity (C ₁ ) 6,000 U / mg * C _x cellulase activity 200 U / mg Measurement conditions Reaction time 30 minutes pH 5.0 Action temperature 50 ° C

This commercially available complex enzyme possesses strong β-glucosidase (cellobiase) activity, xylanase activity and pectinase activity in addition to the above-mentioned enzymes,
It is a very convenient enzyme for carrying out the present invention. As mentioned above, since the lignin decomposition tank has a small effective volume of 5 liters, it is difficult to incorporate the conventional vacuum fermentation system into the experimental apparatus. The fluctuation range is large, which hinders accurate and appropriate evaluation of experimental results.

Then, the two lignin decomposing tanks were automatically vacuum-controlled by a vacuum pump so that the total tanks would be substantially -1,500 mmAq, and vacuum fermentation was carried out. The lignin decomposition tank and the cellulose decomposition tank effluent were subjected to forced separation and removal of suspended solids at 3,000 G for 10 minutes using a centrifuge, and then used as samples for chemical composition analysis. The verification test under the above experimental equipment and conditions continued for 5 months after the operation reached a steady state, and
Table 5 shows the treatment results (average value) for one month.

[0053]

[Table 5] (Note) Amount of gas generated per decomposed organic matter * Hydrogen gas 126 ml / g-Decomposed organic matter * Carbon dioxide gas 52 ml / g-Decomposed organic matter

The experimental results in the lignin decomposition tank and the cellulose saccharification tank are summarized as follows. Experimental results in lignin decomposing tank (1) Even if anaerobic fermentation is performed by injecting cedar lumber sawdust adjusted to a slurry state into the lignin decomposing tank and inoculating this with methane fermentation digestion sludge of sewage sludge as seed sludge, lignin, Substantial decomposition of cellulose did not proceed at all, and methane gas (20-35 ml / g-feed organic matter) and carbon dioxide gas (2
(0 to 25 ml / g-feed organic matter) was observed, but the sawdust did not change visually at all, and the granular morphology did not disintegrate. The experimental results obtained were omitted because they were not particularly effective.

(2) In the fermentation experiment of this control, in the method of the present invention in which the mixed culture solution of the termite intestinal tract microbial community that has been accumulated and cultured in the slurry-like cedar sawdust is injected, the shape of the sawdust is completely destroyed, and the lignin The unique brown color also faded. The decomposition rate of lignin in this verification experiment reached about 75%,
Protozoa and bacteria, which have mutually mutualistic relationships as a termite intestinal microbial community, clearly proved that they utilize lignin as an organic carbon source to acquire living energy and proliferative energy. Was done. It was also confirmed that cellulose was decomposed by about 30% and hemicellulose was decomposed by about 50% simultaneously with lignin.

(3) Decompression degree of 1,50 in lignin decomposition tank
It was demonstrated that lignins and celluloses partially decomposed in this tank were bioconverted to hydrogen as clean energy by performing a 0 mmAq vacuum fermentation. The generation rate of hydrogen gas is about 130 ml / g-decomposed organic matter, and the generation rate of carbon dioxide gas is about 50 ml / g-decomposed organic matter. The method of the present invention is an earth-friendly treatment technology that significantly contributes to the elimination of global warming. It was confirmed that there is.

Experimental Results in Cellulose Saccharification Tank (1) In the lignin decomposition tank effluent, microorganism production C ₁ , C _x
Concentrated culture liquid of aerobic filamentous fungus containing cellulose in a concentrated manner,
In a control experiment in which a commercially available complex cellulose enzyme was added, the presence of monosaccharides was scarcely recognized, and only a slight amount of carbon dioxide gas was generated, and the obtained data was not valuable. Did not present as. The reason is that in the control experiment, lignin is not substantially decomposed in the lignin decomposition tank, so that the celluloses are still strongly protected by the lignin, and the microorganisms and the cellulose enzymes are closely contacted with the cellulose and hemicellulose. It is presumed that it was not possible to do so.

(2) On the other hand, in the verification experiment of the method of the present invention in which the mixed culture solution of the termite intestinal tract microbial community that had been accumulated and cultured, the microorganism-producing enzyme, and the commercially available enzyme were added, lignin and celluloses were found to be substantially Is converted to monosaccharides,
It reached 12.5 g / liter / day in terms of glucose.
In addition, it is about 57% with respect to the total amount of lignin, cellulose, and hemicellulose, which is a conversion rate to a monosaccharide which is worthy of evaluation.

[0059]

As described in detail, the present invention is an innovative invention based on an idea that is completely different from that of the prior art, and has the following operational effects. (1) Agricultural waste, livestock waste, etc., especially lignins,
Practical application of lignins, which had been difficult to decompose microbiologically until now, by adding an accumulated culture solution of termite intestinal microbial community to organic waste containing a large amount of celluloses and further performing vacuum fermentation. Not only can it be decomposed by about 75% at a possible economical cost, but also celluloses can be decomposed with a considerable and high efficiency. With the establishment of the present invention, so-called waste cellulose in agricultural waste and forest waste that could not be effectively used even after taking all means and methods for a long time from the past to the present time is recycled as a valuable resource. The resource saving effect of these recyclings is extremely large.

(2) According to the method of the present invention, not only the decomposition of lignin but also the removal of excess hydrogen produced in the hydrogen transfer system involved in the ATP production of termite intestinal tract microorganisms as clean energy eliminates global warming. Can significantly contribute to (3) Cellulose dissociated from lignin and the lignin constraint is a useful substance due to the action of termite intestinal tract microbial community, microbial production C ₁ , C _X cellulase and commercially available complex cellulase enzyme in the next cellulose saccharification step. It is possible to highly efficiently produce monosaccharides, which are fermentation basic substances for producing sucrose, and it has become possible to saccharify cellulose at an economical level, which has been a long-standing wish in this field. This fact proves that the method of the present invention can be a powerful means for solving the global food crisis and food depletion.

[Brief description of drawings]

FIG. 1 is an overall process diagram of a biological treatment method of the present invention.

[Explanation of symbols]

1: Cellulase-producing bacterium, 2: Commercial cellulase, 3,
4, 8, 9: Inlet tube, 5: Termite intestinal tract microbial community, 6:
Integrated culture tank, 7, 14: Culture liquid, 10: Raw material, 11: Slurry tank, 12: Water, 13: Lignin decomposition tank, 15: Product gas, 16: Hydrogen, 17: Gas separation membrane, 18, 21:
CO ₂ , 19: Cellulose saccharification tank, 22: Monosaccharide

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C12R 1:90)

Claims (2)

[Claims] 1. A biological treatment of woody wastes by a lignin decomposition step of decomposing lignin into hydrogen and lower carbon compounds by a microorganism, and then a cellulose saccharification step of decomposing cellulosic materials into monosaccharides. In this case, a method for biological treatment of woody wastes is characterized by using, as said microorganism, an intestinal microbial community of termites anaerobically cultivated in the presence of C _x cellulase. 2. The method for biological treatment of woody waste according to claim 1, wherein the intestinal microbial community of termites is also used in the cellulose saccharification step.