JP2012055167A - Method for treating cellulose-containing material and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a further practical method for treating a cellulose-containing material, decomposing more cellulose using an ionic liquid.SOLUTION: The cellulose-containing material is processed by bringing the cellulose-containing material into contact with the hydrophobic ionic liquid containing a carbonyl group in a cationic species.

Description

  The present invention relates to a method for treating a cellulose-containing material and use thereof.

  An efficient method for saccharifying cellulose for use in various applications is being sought. As one of such methods, attention is focused on the use of an ionic liquid. It is reported that an ionic liquid is a liquid at normal temperature and solubilizes cellulose due to its ionicity. For example, it has been found that cellulose is solubilized in a chloride-based ionic liquid at about 100 ° C. (Patent Document 1, Non-Patent Document 1).

  Furthermore, attempts have been made to saccharify cellulose solubilized with ionic liquid with cellulase, but it has been reported that cellulase is inactivated in ionic liquid (Non-patent Documents 2 and 3). It has also been reported that cellulose solubilized with an ionic liquid can be decomposed with cellulase for the first time by washing the cellulose with a hydrophilic solvent such as water and then introducing the ionic liquid-solubilized cellulose into water (Non-patent Document 4). Furthermore, a technique of swelling the cellulose with an ionic liquid and then removing the ionic liquid and then performing an enzyme treatment has been attempted (Patent Document 2, Non-Patent Document 5).

  Under these circumstances, it is disclosed that cellulose can be saccharified even in the presence of an ionic liquid by swelling the cellulose with a hydrophilic ionic liquid and then introducing a cellulase aqueous solution into the hydrophilic ionic liquid containing the swollen cellulose. (Patent Document 3).

JP 2005-506401 A US Patent Publication No. 2008/0227162 JP 2009-203454 A

R D. Roger et al., J. Am. Chem. Soc. 124 (18), 4974-4975, 2002 Ohno et al., Polym. Prep. Jpn., 55 (1), 2090, 2006 R D. Roger et al., Green Chem., 5, 443-447, 2003 C A. Schall et al., Biotechnol. Bioeng., 95 (5), 904-910, 2006 Q. Li et al., Bioresour Technol., Vol.100, p3570-3575, 2009

  Among the above prior arts, all except Patent Document 3 are limited to the use of an ionic liquid for pretreatment of cellulose prior to saccharification of cellulose. That is, there is no disclosure of a technique for efficiently decomposing cellulose pretreated with an ionic liquid with cellulase. On the other hand, according to the technique disclosed in Patent Document 3, cellulase can be allowed to act in the presence of a hydrophilic ionic liquid containing cellulose having a relaxed structure. The decomposition saccharification step can be performed efficiently or continuously.

  However, in the method described in Patent Document 3, the hydrophilic ionic liquid and water are mixed with each other during saccharification. For this reason, there has been a problem that many processes and energy are required in the step of recovering the low molecular weight product of cellulose from the mixed solution and the step of recovering and reusing the ionic liquid from the mixed solution. .

  Accordingly, an object of the present invention is to provide a method for treating a cellulose-containing material and the like that can be efficiently performed for recovery of an ionic liquid or a degradation product of cellulose in saccharification of cellulose using an ionic liquid.

  As a result of various studies on efficient enzymatic degradation of cellulose pretreated with an ionic liquid, the present inventors have found that a certain kind of hydrophobic ionic liquid and cellulose have a high affinity, and this hydrophobic ionic liquid. It was found that when water was added to cellulose, cellulose was localized at the interface between the hydrophobic ionic liquid phase and the aqueous phase. Further, it has been found that by containing cellulase in the aqueous phase, a saccharification / decomposition reaction of cellulase localized at the interface occurs. Furthermore, it discovered that the decomposition product of a cellulose was contained in an aqueous phase. According to the disclosure of the present specification, the following means are provided based on these findings.

According to the disclosure of the present specification, there is provided a method for treating a cellulose-containing material, the method comprising contacting the cellulose-containing material with a hydrophobic ionic liquid having a carbonyl group. The hydrophobic ionic liquid may have one or two or more cationic species selected from ionic liquids represented by the following formula.

(In formulas (I) and (II), at least one substituent selected from R _{1 to} R ₄ is represented by the following formula (1). In formulas (III) and (IV), R ₁ and At least one substituent selected from R ₂ is represented by the following formula (1): In formula (V), R ₁ is represented by the following formula (1). (In (IV), the substituent not represented by the following formula (1) independently represents an optionally substituted alkyl group, alkenyl group, alkynyl group or aryl group.)

(In Formula (1), R ₅ represents an optionally substituted diyl group of a hydrocarbon, and R ₆ represents an optionally substituted alkyl group, alkenyl group, alkynyl group, and aryl group.)

Preferably, the cationic species is represented by the following (2).

(In Formula (2), R ₁ and R ₆ each independently represent an alkyl group, an alkenyl group, an alkynyl group, and an aryl group, which may be substituted, and R ₅ represents an optionally substituted hydrocarbon group. Represents a diyl group.)

  Furthermore, the anion species of the ionic liquid may be one or more selected from a perfluoroalkyl group-containing fluorophosphate anion and a perfluoroalkyl group-containing sulfonylimide anion. Furthermore, a step of supplying a hydrophilic solvent for the hydrophobic ionic liquid to the cellulose-containing material after contact with the hydrophobic ionic liquid to form a two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase. You may have. In addition, the hydrophobic ionic liquid may contain lithium chloride, and may include a step of adding lithium chloride or an aqueous lithium chloride solution to the hydrophobic ionic liquid prior to the contacting step.

  According to the disclosure of the present specification, there is provided a method for producing a degradation product of a cellulose-containing material, the step of bringing the cellulose-containing material into contact with a hydrophobic ionic liquid having a carbonyl group, and hydrophilicity to the hydrophobic ionic liquid. Supplying a solvent to form a two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase, and containing the cellulose in the vicinity of the interface between the hydrophobic ionic liquid phase and the hydrophilic solvent phase by cellulase Decomposing the cellulose of the material.

  In the said production method, the process of collect | recovering at least one part of the said hydrophilic solvent phase can also be provided after the decomposition | disassembly process of the said cellulose. Moreover, you may provide the process of collect | recovering at least one part of the hydrophobic ionic liquid phase after the decomposition | disassembly process of the said cellulose.

  Further, according to the disclosure of the present specification, there is provided an ionic liquid composition for cellulose saccharification, which contains a hydrophobic ionic liquid having a carbonyl group. The composition may further contain lithium chloride. Further, it may be obtained by adding an aqueous lithium chloride solution to the hydrophobic ionic liquid. Furthermore, the said hydrophobic ionic liquid may be 1 type, or 2 or more types selected from the ionic liquid represented by the following formula | equation. Furthermore, the composition may include a cellulose-containing material.

  As the anion component of the ionic liquid of the composition, the fluorinated alkyl group-containing anion species is one or more selected from a perfluoroalkyl group-containing fluorophosphate anion and a perfluoroalkyl group-containing sulfonylimide anion. Also good.

  According to the disclosure of the present specification, there is a method for producing a useful substance, the step of dispersing in a cellulose-containing material and a hydrophobic ionic liquid phase having a carbonyl group, and supplying a hydrophilic solvent to the hydrophobic ionic liquid phase. A step of forming a two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase, and cellulose of the cellulose-containing material in the vicinity of the interface between the hydrophobic ionic liquid phase and the hydrophilic solvent phase by cellulase. There is provided a production method comprising a step of decomposing, and a step of producing a useful substance by fermentation of microorganisms using the cellulose degradation product obtained in the cellulose decomposing step as a carbon source.

It is a figure which shows an example of the processing method of the cellulose of this invention, the production method of the degradation product of a cellulose, etc. It is a figure which shows typically the one aspect | mode of the decomposition | disassembly behavior by the presence state of a cellulose containing material or a cellulose in the interface of a hydrophobic ionic liquid phase and a hydrophilic solvent phase, or a cellulose. It is a figure which shows the evaluation result of the addition effect of lithium chloride with respect to hydrophobic ionic liquid. It is a figure which shows the evaluation result of the addition effect of lithium chloride saturated aqueous solution with respect to hydrophobic ionic liquid. It is a figure which shows the evaluation result of the addition effect of salts other than lithium chloride. It is a figure which shows the evaluation result of the addition amount of lithium chloride.

  The present disclosure relates to a method for treating a cellulose-containing material, a method for producing a cellulose degradation product, and the like. According to the disclosure of the present specification, when a cellulose-containing material is brought into contact with a hydrophobic ionic liquid having a carbonyl group in a cationic species, the hydrophobic ionic liquid and the cellulose-containing material have a good affinity, and the hydrophobic ionic liquid Penetrates cellulose-containing materials. When the hydrophobic ionic liquid is present in excess relative to the cellulose-containing material, the cellulose-containing material is dispersed in the hydrophobic ionic liquid. Thereafter, by supplying a hydrophilic solvent such as an aqueous medium to the hydrophobic ionic liquid, a two-phase system of a hydrophobic ionic liquid phase containing a cellulose-containing material and a hydrophilic solvent phase is formed.

  As shown in FIG. 2, in the two-phase system formed by the above processing method, a fraction containing cellulose is localized and concentrated at the interface. At this time, the cellulose-containing material having affinity with the hydrophobic ionic liquid is formed in a state in which cellulose concentrated and localized at the interface is easily accessible by cellulase. On the other hand, cellulase exists in the hydrophilic solvent phase. As a result, cellulose of the cellulose-containing material localized at the interface is easily decomposed by cellulase. At the same time, contact between the cellulase and the hydrophobic ionic liquid is suppressed, and the enzyme activity is easily secured. As a result, cellulose is efficiently decomposed by cellulase.

  The above effect is because cellulose is decomposed in a state where a two-phase system of a certain type of hydrophobic ionic liquid phase and a hydrophilic solvent phase is formed. That is, the cellulose-containing material has an interface between the hydrophobic ionic liquid phase and the hydrophilic solvent phase because a portion having a high affinity for the hydrophilic solvent is generated or exposed by the action of the hydrophobic ionic liquid on the cellulose-containing material. Become localized. And it is thought that cellulase accesses such cellulose and decomposes | disassembles cellulose, disintegration of cellulose further advances by the decomposition, and decomposition by cellulase also advances. The decomposition product of cellulose is transferred to the hydrophilic solvent phase along with the decomposition, and is further reliably decomposed and recovered.

  Further, because of the two-phase system, the hydrophobic ionic liquid itself is easy to separate and recover. In addition, glucose or the like, which is a decomposition product of cellulose, moves to the hydrophilic solvent phase. For this reason, the cellulose degradation product is easily separated and recovered as a hydrophilic solvent phase or from the solvent phase.

  As described above, according to the disclosure of the present specification, when the hydrophobic ionic liquid and the cellulose-containing material are brought into contact with each other and the hydrophobic ionic liquid is infiltrated into the cellulose-containing material, the hydrophilic solvent is subsequently supplied. A two-phase system can be formed. As a result, the cellulose can be efficiently decomposed and recovered by cellulase, and the hydrophobic ionic liquid can be separated and recovered and reused. This also makes it possible to efficiently convert the cellulose-containing material into a useful substance.

  Hereinafter, various embodiments disclosed in this specification will be described in detail with reference to the drawings as appropriate. FIG. 1 is a diagram showing an example of an outline of a method for treating a cellulose-containing material, a method for producing a cellulose degradation product, and a method for producing a useful substance disclosed in the present specification, and FIG. 2 shows a hydrophobic ionic liquid phase. It is a figure which shows typically the one aspect | mode of the decomposition | disassembly behavior of the cellulose in the interface of a two phase system with a hydrophilic solvent phase.

(Cellulose-containing material)
In the present specification, cellulose refers to a polymer in which glucose is polymerized by β-1,4-glucoside bonds and derivatives thereof. The degree of polymerization of glucose in cellulose is not particularly limited, but is preferably 200 or more. In addition, examples of the derivative include derivatives such as carboxymethylation, aldehyde formation, or esterification. Cellulose may contain cellooligosaccharide and cellobiose, which are partially decomposed products thereof. Further, the cellulose may be a complex with β-glucoside, which is a glycoside, lignocellulose, which is a complex with lignin and / or hemicellulose, and pectin. The cellulose may be crystalline cellulose or non-crystalline cellulose, but preferably contains crystalline cellulose. Furthermore, the cellulose may be naturally derived or artificially synthesized. The origin of cellulose is not particularly limited. It may be derived from plants, fungi, or bacteria.

  In addition, cellulose naturally exists as a main component of plant cell walls, and is most produced as a polysaccharide on the earth. In the plant cell wall, the cellulose forms a crystalline cellulose region and an amorphous cellulose region. Cellulose forms a cellulose-containing matrix complexed with lignin and hemicellulose on the plant cell wall.

  In the present specification, the cellulose-containing material may be any material that contains cellulose as described above. Therefore, the cellulose may be crystalline cellulose or amorphous cellulose, and may contain hemicellulose or lignin in addition to cellulose. Cellulose-containing materials include natural fiber products such as cotton and linen, recycled fiber products such as rayon, cupra, acetate and lyocell, various straws such as rice straw, agricultural waste such as rice husks, bagasse and wood chips, waste paper, construction Biomass (woody and herbaceous) containing various wastes such as waste materials.

  The cellulose-containing material applied to the various embodiments disclosed in the present specification is not particularly limited. As disclosed in the examples described later, it has been found that the hydrophobic ionic liquid disclosed in the present specification can be solubilized, disintegrated, or dissolved even if it is crystalline cellulose. In other words, even in a highly crystalline region that interacts strongly due to hydrogen bonding, such as crystalline cellulose, the hydrophobic ionic liquid can permeate and permeate, relax its structure and promote cellulase degradation. . Therefore, if the hydrophobic ionic liquid can act on the disintegration / solubilization or dissolution of the matrix containing cellulose, it is considered that the cellulose-containing material can be applied to this treatment method. In consideration of the action of the hydrophobic ionic liquid on the cellulose-containing matrix, the cellulose-containing material is preferably insoluble or hardly soluble in water. Examples of the cellulose-containing material include a cellulose-containing material containing crystalline cellulose, and examples thereof include a material containing a cellulose-containing matrix derived from a plant cell wall containing lignin and / or hemicellulose in addition to cellulose. Typically, herbaceous or woody biomass is mentioned.

(Method for treating cellulose-containing material)
The method for treating a cellulose-containing material disclosed in the present specification can include a step of contacting the cellulose-containing material and a hydrophobic ionic liquid having a carbonyl group (hereinafter referred to as a contacting step). Further, the treatment method disclosed in the present specification is to supply a hydrophilic solvent for the hydrophobic ionic liquid to the cellulose-containing material after contact with the hydrophobic ionic liquid, thereby providing the hydrophobic ionic liquid phase and the hydrophilic solvent phase. A step of forming a two-phase system (hereinafter referred to as a two-phase system forming step) can also be provided.

(Contact process)
The contact step disclosed in the present specification is a step of bringing a hydrophobic ionic liquid that is a liquid phase into contact with a cellulose-containing material that is a solid phase. The hydrophobic ionic liquid having a carbonyl group has affinity or permeability to the cellulose-containing matrix of the cellulose-containing material, and can disintegrate at least a part of the cellulose-containing material and relax its structure. Although not restricting the disclosure of this specification, since cellulose is a polymer material having both a hydrophobic region and a hydrophilic region, the hydrophobic ionic liquid is caused by the interaction between the hydrophobic region and the hydrophobic ionic liquid. Is believed to penetrate the cellulose-containing matrix and destroy at least a portion thereof. In addition, when the cellulose-containing material has a cellulose-containing matrix containing hemicellulose or lignin in addition to cellulose, similarly, it interacts with the hydrophobic regions of these components and penetrates into the cellulose-containing matrix. It is thought that a part will collapse.

(Hydrophobic ionic liquid)
In the present specification, the hydrophobic ionic liquid refers to an ionic liquid that is two-phase separated from water. It may be an ionic liquid that is two-phase separated from water by temperature change. The hydrophobic ionic liquid applied to the contact step is not particularly limited as long as it is a hydrophobic ionic liquid having a carbonyl group as a cationic species. Such a hydrophobic ionic liquid is, for example, a hydrophobic ionic liquid that is permeable to a cellulose-containing material. When mixed with a cellulose-containing material, the cellulose-containing material suppresses the downward accumulation of the hydrophobic ionic liquid. It can be suspended or dispersed. Also, cellulase access in the hydrophilic solvent phase can be facilitated after contact with the hydrophobic ionic liquid.

  The melting point of the ionic liquid is preferably 100 ° C. or lower, more preferably 80 ° C. or lower. More preferably, it is 40 degrees C or less, Most preferably, it is 20 degrees C or less.

  Examples of the hydrophobic ionic liquid include quaternary ammonium salts, quaternary phosphonium salts, substituted imidazolium salts substituted with hydrocarbon groups, substituted pyridinium salts, substituted pyrrolidinium salts (alicyclic quaternary ammonium salts). ), Tertiary sulfonium salts and the like, and the hydrophobic ionic liquid of the present invention is preferably a quaternary ammonium salt, a quaternary phosphonium salt, a substituted imidazolium salt, a substituted pyridinium salt or a substituted pyrrolidinium salt. However, quaternary ammonium salts and quaternary phosphonium salts are preferred. A quaternary ammonium salt, a quaternary phosphonium salt, a substituted imidazolium salt, a substituted pyrrolidinium salt, and a substituted pyridinium salt are represented by general formulas (I) to (V), respectively.

  As the basic skeleton of the cation species constituting the hydrophobic ionic liquid, as shown in the general formula (I), an ammonium cation having the same or different four substituents bonded to the nitrogen atom, as shown in the general formula (II) A phosphonium cation in which four identical or different substituents are bonded to a phosphorus atom, an imidazolium cation in which two nitrogen atoms of an imidazole ring are bonded to the same or different substituents as shown in the general formula (III), A pyrrolidinium cation in which the nitrogen atom on the pyrrolidine ring is bonded to a substituent as shown in formula (IV), and a pyridinium cation in which the nitrogen atom on the pyridine ring is bonded to a substituent as shown in general formula (V) And sulfonium cations in which three identical or different substituents are bonded to a sulfur atom.

  Preferred basic cation species include imidazolium cations in which two nitrogen atoms of the imidazole ring are bonded to the same or different substituents, pyridinium cations in which the nitrogen atoms on the pyridine ring are bonded to substituents, and pyrrolidine rings. Examples include pyrrolidinium cations in which a nitrogen atom is bonded to a substituent. In addition, these cyclic bodies may form a polycyclic structure in which two are connected.

It is preferable that at least one substituent of the substituents in these cationic species (represented by R _{1 to} R ₄ in the general formulas (I) to (V)) has a carbonyl group. The carbonyl group may be at the end of the substituent or in the vicinity of each ring. The carbonyl group may have an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or an alkyl-substituted amino group at the carbon atom. Examples of the substituent having such a carbonyl group include a substituent represented by the following formula (1).

In the formula (1), R ₅ represents an optionally substituted diyl group of a hydrocarbon, and R ₆ represents an optionally substituted alkyl group, alkenyl group, alkynyl group or aryl group. In the formula (1), R ₅ represents an optionally substituted diyl group of a hydrocarbon, and R ₆ represents an optionally substituted alkyl group, alkenyl group, alkynyl group or aryl group.

Preferably, the cationic species is represented by the following (2).

In the formula (1), R ₁ and R ₆ each independently represent an alkyl group, an alkenyl group, an alkynyl group and an aryl group, which may be substituted, and R ₅ represents a diyl of an optionally substituted hydrocarbon. Represents a group. Examples of the hydrocarbon diyl group include an alkylene group having about 1 to 18 carbon atoms, an alkenylene group, and an alkynylene group. Preferably it is a C1-C6 grade, More preferably, it is a C1-C4 alkylene group. The hydrocarbon diyl group may have a benzene ring which may be substituted with an alkyl group or the like, and the two yl groups may be on the benzene ring, or one of them may be on the benzene ring. And the other may be on the substituent or both may be on the substituent. For example, examples of the diyl group of hydrocarbon include a methylene group and a diyl group represented by the following formula (3).

Substituents R _{1 to} R ₄ other than the substituent having a carbonyl group each independently have 1 to 18 carbon atoms and are a linear or branched alkyl group, alkenyl group, alkynyl group, and aryl group. Is preferred. Preferable alkyl groups include linear alkyl groups having 1 to 18 carbon atoms. Specifically, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, n- A dodecyl group, a tetradecyl group, a hexadecyl group, etc. are mentioned. Further, it may be an aromatic hydrocarbon group such as a benzyl group, a benzal group, or a benzylidene group. Preferred alkenyl groups include allyl groups (2-propenyl groups) optionally substituted with lower alkyl groups and the like. In addition, the substituent may have an alkoxy group having an alkyl group having about 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, and an n-butyl group. Preferably, an alkoxy group is provided at the end of the alkyl chain, such as a 2-methoxyethyl group.

Preferred anionic species are exemplified by the following formulas (4) to (6).

Examples of the constituent anion species of the hydrophobic ionic liquid include substitution with bis (perfluoroalkane) sulfonimide anion and perfluoroalkane group such as bis (trifluoromethane) sulfonimide anion ((CF ₃ SO ₂ ) ₂ N ⁻ ) Hexafluorophosphate anion (PF ₆ ⁻ ) optionally substituted with a perfluoroalkane group such as hexafluoroantimonate anion (SbF ₆ ⁻ ), tris (pentafluoroethyl) trifluorophosphate anion, A tetrafluoroborate anion (BF ₄ ⁻ ) optionally substituted with a fluoroalkane group, a halogen anion such as a chlorine anion (Cl ⁻ ), a bromine anion (Br ⁻ ), an iodine anion (I ⁻ ), an alkanesulfonate anion, Perfluoroal Emissions sulfonate anion (CF ₃ SO ₃ ^-, etc.), acetate anion (CH ₃ CO ₂ ^-), perfluoro acid anion (CF ₃ CO ₂ ^-), nitrate anion (NO ₃ ^-) and the like.

Preferred anionic species include fluorinated alkyl group-containing anionic species. The fluorinated alkyl group is preferably a perfluoroalkyl group. Examples of such anion species include perfluoroalkyl group-containing sulfonylimide anions such as bis (trifluoromethane) sulfonimide anion ((CF ₃ SO ₂ ) ₂ N ⁻ ) and tris (pentafluoroethyl) trifluorofate anion. Examples include perfluoroalkyl group-containing fluorophosphate anions.

  The ionic liquid is composed of a combination of a cation species and an anion species, and conventionally known cation species and anion species including the above-described cation species and anion species can be used in appropriate combination. The hydrophobic ionic liquid can be synthesized by a known method except that it is commercially available. The synthesis method is not particularly limited, and the cation is synthesized and purified as a salt with chloride, and then reacted with the anion salt of the ionic liquid to be obtained, or once converted into a hydroxide, You may neutralize with the acid which contains.

The hydrophobic ionic liquid can include lithium chloride. Lithium chloride is an ionic compound, and it is considered that some or all of them are present as Li ⁺ ions and Cl ^- ions in the hydrophobic ionic liquid. When lithium chloride is present in a hydrophobic ionic liquid in which the cationic species has a carbonyl group, the saccharification rate of cellulose is improved. Therefore, it is considered that the structural relaxation of cellulose was promoted by the coexistence of the cation species having a carbonyl group and lithium chloride. This is considered to be due to chlorine ions having high hydrogen bonding ability. It has been found that KCl and NaCl do not provide the effect of addition like LiCl. Therefore, it is considered that Li salt is also involved. The above-described action due to the addition of lithium chloride is inference and does not constrain the disclosure of this specification.

  Lithium chloride may be supplied to the hydrophobic ionic liquid in a solid state, or may be supplied to the hydrophobic ionic liquid in the form of a saturated aqueous solution. When supplied in the form of a saturated aqueous solution, the structural relaxation of cellulose is considered to be further promoted. That is, a good saccharification rate can be obtained even when the contact step is performed at a low temperature or the contact step is performed at 60 ° C. to 100 ° C. for about 1 hour to 6 hours.

  The addition amount of lithium chloride is not particularly limited, but is preferably about 0.05% by mass or more and 20% by mass or less with respect to the total amount with the hydrophobic ionic liquid. If the amount is too large, the cellulase activity may be affected. If the amount is too small, the effect of addition cannot be obtained sufficiently. More preferably, it is 0.1% by mass or more, and further preferably 1% by mass or more. Further, it is preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 2% by mass or less.

  The purity of the ionic liquid is preferably high. This is because impurities in the process of synthesizing the ionic liquid greatly affect the pH of the medium obtained by mixing the ionic liquid and the hydrophilic solvent, and as a result, may greatly affect the catalytic activity of the enzyme. According to the present inventors, for example, in the case of an ionic liquid using an imidazolium cation, the lower the purity, the easier the pH when mixed with a hydrophilic solvent such as water or a buffer solution is shifted to alkali, and cellulose by cellulase It has been found that the degradation activity tends to decrease.

  The above hydrophobic ionic liquids can be used alone or in combination of two or more. Such a hydrophobic ionic liquid or a combination thereof is useful as a medium for structural relaxation, decomposition and saccharification of cellulose-containing materials. According to such a medium, cellulose can be efficiently decomposed with cellulase, and the recovery and reuse of the medium and the recovery of decomposition products can be facilitated.

  The method for bringing the cellulose-containing material into contact with the hydrophobic ionic liquid is not particularly limited. The cellulose-containing material only needs to be compatible with the hydrophobic ionic liquid, and it is not always necessary that the cellulose-containing material is immersed, dispersed, or suspended in the hydrophobic ionic liquid. In order to bring the hydrophobic ionic liquid into contact with the cellulose-containing material, for example, as shown in FIG. 1, the cellulose-containing material may be supplied into a sufficient amount of the hydrophobic ionic liquid. Alternatively, the hydrophobic ionic liquid may be supplied in such an amount as to wet the cellulose-containing material by spraying or the like, and the cellulose-containing material may be impregnated with the hydrophobic ionic liquid.

  The treatment for allowing the hydrophobic ionic liquid to penetrate into the cellulose-containing material can be appropriately set. For example, it may be heated to about 40 ° C. or higher and 150 ° C. or lower, preferably 50 ° C. or higher and 150 ° C. or lower. By heating, penetration of the hydrophobic ionic liquid into the cellulose-containing material can be promoted, and decomposition can be promoted by cellulase. If it exceeds 150 ° C., an undesirable reaction may occur depending on the type of the cellulose-containing material, and if it is less than 40 ° C., it is difficult to obtain the effect of heating. Moreover, you may stir as needed. Further, ultrasonic treatment may be performed. These various treatments may be employed alone or in appropriate combination. The type of treatment is appropriately changed depending on the type of hydrophobic ionic liquid used and the cellulose-containing material.

  In the subsequent two-phase formation process, in order to reduce the amount of hydrophobic ionic liquid, a sufficient amount of hydrophobic ionic liquid necessary for permeation may be supplied to the cellulose-containing material, or a sufficient amount of hydrophobic ionic liquid may be supplied. The cellulose-containing material immersed in the liquid may then be separated from the hydrophobic ionic liquid by solid-liquid separation means such as filtration or centrifugation.

  By carrying out such a contact step, it is considered that the hydrophobic ionic liquid is compatible with the cellulose-containing material, and the cellulose-containing matrix is loosened. The structure of the cellulose-containing material is relaxed by the hydrophobic ionic liquid, so that when the two-phase system is formed in contact with a hydrophilic solvent such as an aqueous medium, the hydrophilic region of cellulose is the interface with the hydrophilic solvent phase. It is considered that the cellulose at the interface is decomposed by cellulase in the hydrophilic solvent phase. Therefore, the cellulose-containing material into which the hydrophobic ionic liquid has been permeated through such a contact step can be used for the subsequent decomposition of cellulose by cellulase or the like.

(Two-phase formation process)
Furthermore, the processing method disclosed in the present specification may include a two-phase system forming step. A two-phase system can be constructed by supplying a hydrophilic solvent to a cellulose-containing material infiltrated with a hydrophobic ionic liquid. Thereby, the cellulose-containing material can be localized and concentrated at the interface with the hydrophilic solvent phase, and an environment suitable for decomposing cellulose by cellulase or the like can be formed.

  The liquid supplied to the hydrophobic ionic liquid can form a two-phase system with the hydrophobic ionic liquid (the solvent is hydrophilic enough to form a two-phase system with the hydrophobic ionic liquid). Any hydrophilic solvent that is a good solvent for glucose among cellulose degradation products may be used. Moreover, the hydrophobic ionic liquid used here may be used by mixing two or more different types. Examples of such a liquid include an aqueous liquid and a mixed liquid of water or an organic solvent compatible with water.

  Examples of the organic solvent include lower alcohols having about 1 to 4 carbon atoms. In addition, the liquid may contain an acid, an alkali, or a salt for dissolving glucose or the like, which is a decomposition product of cellulose, or for forming a pH or salt concentration suitable for an enzymatic reaction with cellulase. Typically, a buffer solution or a salt solution that can give a pH suitable for an enzyme reaction to the hydrophilic solvent phase at the time of forming a two-phase system can be mentioned. The hydrophilic solvent can also contain metal ions necessary for the enzyme reaction. Furthermore, an enzyme may be previously contained in cellulase or the like. Salts and enzymes in consideration of the enzyme reaction are not necessarily required to be included in the hydrophilic solvent in the two-phase system formation step. You may make it add these at the time of decomposition | disassembly of a cellulose at least.

  The method for forming the two-phase system and the form of the two-phase system are not particularly limited. A hydrophilic solvent may be supplied to the cellulose-containing material dispersed or suspended in the hydrophobic ionic liquid, or a hydrophilic solvent may be supplied to the cellulose-containing material only impregnated with the hydrophobic ionic liquid. Good. Prior to contact with the hydrophilic solvent, an excessive amount of the hydrophobic ionic liquid may be removed by solid-liquid separation, if necessary. In forming the two-phase system, the cellulose-containing material and the hydrophilic solvent may be appropriately stirred in order to sufficiently contact them. Further, it may be accompanied by heating at an appropriate temperature.

  As shown on the left side of FIG. 1, when the cellulose-containing material is held in a dispersed or suspended state in the hydrophobic ionic liquid phase, an apparent two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase Become. On the other hand, as shown on the right side of FIG. 1, when the hydrophobic ionic liquid penetrates into the cellulose-containing material but does not exist in an excessive amount with respect to the cellulose-containing material, the hydrophobic ionic liquid is contained in the hydrophilic solvent. It becomes a two-phase system in which there is a cellulose-containing material that has penetrated. In the latter two-phase system, the cellulose-containing material itself is a substantially hydrophobic ionic liquid phase. Even in such a case, it can be said that the cellulose-containing material is localized in the vicinity of the interface with the hydrophilic solvent phase.

  By carrying out such a two-phase formation process, the cellulose-containing material is localized and concentrated at the interface between the hydrophobic ionic liquid phase and the hydrophilic solvent phase. This is presumed to be due to the interaction with the hydrophilic solvent phase with a hydrophilic region such as cellulose contained in the cellulose-containing material. At the two-phase interface, it is presumed that the hydrophilic region is exposed to the hydrophilic solvent phase side. Such localization and concentration of the cellulose-containing material and exposure to the hydrophilic solvent phase are in a state suitable for cellulose degradation by cellulase present in the hydrophilic solvent phase. At the same time, the two-phase system has become a preferred system for recovery of hydrophobic ionic liquids and recovery of degradation products.

  As described above, according to the method for treating a cellulose-containing material disclosed in the present specification, the structure of the cellulose-containing matrix of the cellulose-containing material can be relaxed to form an environment in which cellulase is easily accessible. it can. Furthermore, by forming a two-phase system, it is possible to form an environment suitable for cellulose degradation by cellulase and suitable for separation and recovery of both hydrophobic ionic liquid and degradation products.

(Ionic liquid composition for cellulose saccharification)
According to the disclosure of the present specification, there is provided an ionic liquid composition for saccharification of cellulose, which contains a hydrophobic ionic liquid having a carbonyl group. According to the present composition, the cellulose-containing material can be permeated and a pretreatment suitable for the subsequent decomposition saccharification reaction by cellulase can be performed. The present composition may contain lithium chloride, or may be obtained by adding an aqueous lithium chloride solution. As the hydrophobic ionic liquid, various hydrophobic ionic liquids already described can be used alone or in combination of two or more. The present composition may contain a cellulose-containing material. Moreover, the hydrophilic solvent which forms a two-phase system with hydrophobic ionic liquid may be included.

  Such a composition uses cellulose as a cellulose-containing material as a substrate and cellulase as an enzyme. However, other substances and their decomposition can be used as long as they are substrate-containing materials that exert a structure relaxation action by a hydrophobic ionic liquid. It can also be applied to enzymes. That is, even if it takes a form of a substrate that is hardly soluble in an environment where the enzyme can operate, it can be easily used by allowing the enzyme to act by permeating the hydrophobic ionic liquid.

  The substrate is not particularly limited, and examples thereof include natural polysaccharides and natural resins, and polymers containing synthetic polysaccharides and synthetic resins. Examples of natural polysaccharides include cellulose, xylan, chitin, and chitosan. In addition, the enzyme depends on the type of substrate, but when cellulose is used as the substrate, it is the cellulase already described. Examples of xylan include xylanase, and examples of chitin and chitosan include chitinase.

  The hydrophobic ionic liquid can be preferably used for chitin and chitosan having a similar structure.

  In order to prepare a reaction medium that can suppress or avoid adverse effects on the enzyme activity and degradation efficiency due to fluctuations in the properties of the hydrophobic ionic liquid, the ionic liquid used and the hydrophilic solvent are in contact with each other. It is preferred to use a hydrophilic solvent that has sufficient adjustment capability to correct for pH shifts that may occur or to buffer pH fluctuations. The composition may further contain an enzyme for acting on the substrate. The enzyme may be added in advance to a hydrophilic solvent, or may be added after forming a two-phase system.

(Production method of degradation products of cellulose-containing materials)
According to the disclosure of the present specification, as shown in FIG. 1, there is provided a method for producing a degradation product of a cellulose-containing material comprising the contact step, the two-phase system formation step, and the cellulose degradation step. According to the production method disclosed in the present specification, it is suitable for the decomposition of cellulose by cellulase, and furthermore, a two-phase system suitable for the separation and recovery of hydrophobic ionic liquid and the recovery of degradation products such as glucose. Therefore, the cellulose-containing material can be decomposed and utilized at a practical level. In addition, regarding the contact process and the two-phase system formation process, various aspects described in the processing method can be applied as they are. In addition, as a decomposition product of cellulose, any cellulose may be used as long as the molecular weight is reduced. More specifically, there are cellobiose and cellooligosaccharide in addition to glucose which is the final degradation product.

(Cellulose decomposition process)
The cellulose decomposition step is a step of decomposing cellulose with cellulase in the hydrophilic solvent phase. Cellulase is a general term for various enzymes that act to hydrolyze cellulose to glucose. As cellulases, β1,4-endoglucanase (EC 3.2.1.4), glucan 1,4-β glucosidase (EC 3.2.1.74), cellulose 1,4-β cellobiosidase (EC 3) are narrowly defined. 2.1.91), β-glucosidase (EC 3.2.1.21) and the like. The cellulase may be naturally derived or artificially modified. Although it does not specifically limit as a thing of natural origin, The cellulase derived from the genus Trichoderma or Aspergillus etc. can be used preferably. A thermostable cellulase that exhibits high activity at 70 ° C. or higher and maintains activity at 90 ° C. to 100 ° C. can also be used. For example, it may be a cellulase derived from a hyperthermophilic archaea represented by the genus Pyrococcus. In the present invention, the above-mentioned narrowly defined cellulases can be used singly or in combination of two or more. Instead of different types of cellulases, they may be the same type or a combination of two or more types. In addition, cellulases having different origins can be used in combination. The cellulase may be in a form held on a suitable carrier.

  In the cellulose decomposition step, an enzyme that decomposes hemicellulose forming a complex with cellulose in the plant cell wall can also be used. Examples of hemicellulose include xylan, mannan, glucomannan and the like. Examples of hemicellulose-degrading enzymes include xylanases, and these enzymes may be derived from cellulose-degrading microorganisms such as the genus Trichoderma and Aspergillus. Further, it may be a thermostable cellulase such as a cellulase derived from a hyperthermophilic archaea represented by the genus Pyrococcus.

  Cellulase may be included in the hydrophilic solvent in advance in the two-phase system formation step, or may be added to the hydrophilic solvent phase in the cellulase decomposition step. At the time of addition of cellulase, the hydrophilic solvent phase is preferably an environment suitable for expression of enzyme activity. Considering the stability of the enzyme reaction and the ease of operation, the hydrophilic solvent phase should be a buffer solution having a buffer capacity in a range that matches the pH range suitable for the enzyme activity including the optimum pH of the cellulase used. preferable. Since typical preferred pH of general cellulase is about 4 to 6, for example, citrate buffer (citric acid and sodium citrate), acetate buffer (acetic acid-sodium acetate), citrate-phosphate buffer Liquid (citric acid-sodium dihydrogen phosphate) and the like. It is preferable to appropriately adjust the concentration and pH of such a buffer solution and set the pH of the hydrophilic solvent phase to 4 or more and 6 or less, more surely 4.0 or more and 6.0 or less.

  The temperature and time for cellulose degradation by cellulase are not particularly limited. Although it depends on the type of cellulase, it is usually about 30 ° C. to 70 ° C., preferably about 35 ° C. to 45 ° C., pH 2 or more and about 6 or less, and is performed for several hours to several tens of hours. When thermostable cellulase is used, it may be 70 ° C. or higher and 100 ° C. or lower.

  According to the cellulose decomposition step, the structure of the cellulose matrix is relaxed by the hydrophobic ionic liquid and a two-phase system in which a part is exposed at the interface with the hydrophilic solvent phase is formed. Cellulase can efficiently decompose cellulose. In addition, low molecular weight products of cellulose such as glucose (degradation products containing disaccharides and oligosaccharides) migrate to the hydrophilic solvent phase, and are thus more easily decomposed by cellulase. As will be described later, the decomposition product can be easily recovered from the hydrophilic solvent phase.

  By carrying out such a cellulose decomposition step, for example, as shown in FIG. 2, cellulose is decomposed by cellulase, and the molecular relaxation is further promoted by such low molecular weight, and decomposition by cellulase is also promoted. In addition, the decomposition product may be transferred to the hydrophilic solvent phase and further decomposed by cellulase. On the other hand, as will be described later, carbon sources derived from cellulose, such as undegraded cellulose, hemicellulose, and lignin, are separated as a solid phase by solid-liquid separation means, and thus can be subjected to treatment such as decomposition again. The loss of the raw material can be sufficiently suppressed or avoided. Further, as will be described later, the hydrophobic ionic liquid can also be easily separated and recovered and reused.

(Decomposition product recovery process)
As shown in FIG. 1, at least a portion of the hydrophilic solvent phase can be recovered after the cellulose decomposition step. The two-phase system is maintained after the decomposition process and the hydrophilic solvent phase is easily recovered. Usually, the hydrophobic ionic liquid phase has a higher specific gravity than the hydrophilic solvent phase, and the hydrophilic solvent phase is the upper phase and the hydrophobic ionic liquid phase is the lower phase. Therefore, usually, the upper phase may be recovered. Since the recovered hydrophilic solvent phase does not substantially contain a hydrophobic ionic liquid, it can be used as it is, for example, in a fermentation step in a production method of useful substances described later. Moreover, you may concentrate as needed. The hydrophilic solvent phase contains cellulase, but can be separated and recovered by a known method. Separation and recovery are facilitated by immobilizing cellulase on a solid support.

(Recovery process of hydrophobic ionic liquid)
As shown in FIG. 1, at least a part of the hydrophobic ionic liquid can be recovered after the cellulose decomposition step. Due to the two-phase system, the hydrophobic ionic liquid is easily recovered. Further, as shown in FIG. 1, the recovered hydrophobic ionic liquid phase can be reused or recycled as a hydrophobic ionic liquid to be supplied again to the contacting step and permeate the cellulose-containing material. Since the hydrophobic ionic liquid is expensive, the saccharification of cellulose becomes more realistic by enabling such circulation use. The hydrophobic ionic liquid has a structure relaxation action of the cellulose-containing matrix, but does not dissolve cellulose. The water-soluble fraction is transferred to the hydrophilic solvent phase, and the undecomposed solid phase (decomposition residue of the cellulose-containing material) is separated by solid-liquid separation means as will be described later. Therefore, dissolution of the cellulose-containing material-derived component in the hydrophobic ionic liquid phase is avoided or suppressed.

  Note that the decomposition residue of the cellulose-containing material remaining due to localization at the interface can be recovered by solid-liquid separation means. Such a residue can be subjected again to the contact step to the decomposition step. The residue is considered to contain hemicellulose, lignin, undegraded cellulose, etc., depending on the type of cellulose-containing material used and the type of cellulase.

  As described above, according to the method for producing a cellulose degradation product disclosed in the present specification, it is possible to use a more practical cellulose-containing material that facilitates recovery of the used hydrophobic ionic liquid and cellulose degradation product. It becomes.

(Useful substance production method)
The method for producing useful substances using cellulose disclosed in the present specification is to produce useful substances by fermentation of microorganisms such as yeast using the cellulose degradation product obtained by the above-described method for producing cellulose degradation products as a carbon source. Step (hereinafter, also simply referred to as a fermentation step). According to this production method, the manufacturing cost as a whole can be reduced by using the cellulose degradation product efficiently decomposed and recovered from the cellulose-containing material.

  The carbon source includes a cellulose-containing material infiltrated with a hydrophobic ionic liquid and a hydrophilic solvent containing cellulase, and in the cellulose-containing material in a two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase. The cellulose degradation product in the hydrophilic solvent phase obtained by decomposing cellulose is used. The cellulose degradation product used in this production method may be separated and recovered from the hydrophilic solvent phase after the cellulose decomposition step, its concentrate, or the hydrophilic solvent phase. As described above, since the hydrophilic solvent phase does not substantially contain the hydrophobic ionic liquid, it can be used as it is for the fermentation process. Therefore, for example, the hydrophilic solvent phase after the cellulose decomposition step and the like can be used as a part of the fermentation medium.

  The microorganism used in the fermentation process is not particularly limited, and is appropriately selected according to the type of useful substance that can assimilate the degradation product of cellulose and is to be produced. The cellulose degradation product is mainly glucose, but may be xylan derived from hemicellulose. For example, fungi such as yeast and mold, and microorganisms such as E. coli. The microorganism may be a wild type, artificially modified so as to efficiently assimilate cellulose degradation products by genetic engineering techniques, etc., or modified so that useful substances can be produced. Also good. A typical example is a microorganism such as yeast that produces ethanol. Moreover, the yeast and lactic acid bacteria which produce an organic acid may be sufficient.

  What is necessary is just to implement a fermentation process according to the kind of microorganisms to be used and the useful substance which it is going to produce. For the culture for fermentation, stationary culture, shaking culture, aeration-agitation culture, or the like can be used. The aeration conditions can be appropriately selected from anaerobic conditions, microaerobic conditions, aerobic conditions, and the like. The culture temperature is not particularly limited, but may be in the range of 25 ° C to 55 ° C. Moreover, although culture | cultivation time is also set as needed, it can be set as several hours-about 150 hours. The pH can be adjusted using an inorganic or organic acid, an alkaline solution, or the like. During the culture, antibiotics such as ampicillin and tetracycline can be added to the medium as necessary. In addition, after completion | finish of a conversion process, you may implement the process of removing microorganisms from a culture solution, collect | recovering fractions containing useful substances, such as ethanol, and also concentrating this.

  Although it does not specifically limit as a useful substance, The thing which can produce | generate microorganisms using glucose is preferable. For example, there are materials targeted by biorefinery technology, such as ethanol and other lower alcohols, fine chemicals (coenzyme Q10, vitamins and their raw materials, etc.) by adding an isoprenod synthesis pathway, glycerin by modification of glycolysis, and raw materials for plastics and chemical products. Can be mentioned.

  As described above, according to the useful substance production method disclosed in the present specification, the cellulose degradation product obtained more efficiently than the conventional method is used, so the production cost of the useful substance is effectively reduced. Can be reduced.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to a following example.

(Evaluation of addition effect of lithium chloride to hydrophobic ionic liquid)
In the saccharification and recovery of cellulose in a two-phase system using a hydrophobic ionic liquid, the following examination was conducted on the glucose saccharification efficiency when lithium chloride was added. In this study, the following four types of hydrophobic ionic liquids were used as models.
3- [2- (dimethylamino) -2-oxoethyl] -1-methylimidazolium bis (trifluomethylsulfonyl) imide
(Hereafter referred to as [DMAcmim] [Tf2N]. Created by synthesis)
3- [2- (diethylamino) -2-oxoethyl] -1-methylimidazolium bis (trifluomethylsulfonyl) imide
(Hereafter referred to as [DEAcmim] [Tf2N]. Created by synthesis)
3- (4-acetylphenethyl) -1-methylimidazolium bis (trifluomethylsulfonyl) imide
(Hereafter referred to as [AcPEmim] [Tf2N]. Created by synthesis)
l-Ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide
(Solvent innovation, hereinafter referred to as [Emim] [Tf ₂ N])

  The structural formulas of the four types of hydrophobic ionic liquids used in this example are as follows.

(1) 1 wt% (5 mg) of anhydrous LiCl was added to 495 mg of each hydrophobic ionic liquid shown above to prepare 500 mg of hydrophobic ionic liquid. A sample composed of 500 mg of hydrophobic IL-free hydrophobic IL was also prepared. Respectively, crystalline Oh Ru Avicel 1 wt% of (Sigma) cellulose (5 mg) was added and stirred for 3 hours under heating at 0.99 ° C.. After cooling to room temperature, 500 μl of 1 mg / ml cellulase (from Tricoderma ressei, Sigma) aqueous solution (100 mM citrate buffer solution) was added to each sample to form a two-phase system. The saccharification reaction was carried out by stirring at 40 ° C., and each sample was taken 24 hours later.

  Next, the amounts of glucose and cellobiose in the solution were measured. The measurement was carried out by derivatization with 4-aminobenzoic acid ethyl ester (ABEE) reagent. The scheme is shown below. To a 1.5 ml Eppendorf tube, 10 μl of sample and 40 μl of ABEE-labeled reagent were added, vortexed and centrifuged (8000 rpm, 1 minute, 20 ° C.), and then incubated at 80 ° C. for 60 minutes using a block incubator. Milli-Q water (200 μl) and chloroform (200 μl) were added, vortexed and centrifuged (8000 rpm, 3 minutes, 20 ° C.), and the aqueous phase was recovered. The recovered aqueous phase was subjected to HPLC analysis to determine the amount of sugar produced. The composition of the ABEE solution and the HPLC analysis conditions are shown in the table below.

Based on the obtained glucose concentration, the conversion efficiency to sugar when the crystalline cellulose added before the reaction was taken as 100 was calculated according to the following formula.
Glucose conversion efficiency (%) = [produced glucose] / [glucose units in cellulose] ´ 100

The results of the saccharification reaction after 24 hours are shown in FIG. As shown in FIG. 3, an increase in the saccharification rate was confirmed by adding lithium chloride to any ionic liquid containing a carbonyl group in the molecular structure of the ionic liquid synthesized in this example. On the other hand, in [Emim] [Tf ₂ N] that does not contain a carbonyl group in the molecular structure, no increase in saccharification rate was observed with the addition of lithium chloride. This suggests that the structure relaxation effect of the cellulose chain may be enhanced by the high hydrogen-bond Cl ⁻ resulting from the interaction between lithium chloride partially dissolved in the ionic liquid and the carbonyl group of the ionic liquid. It was.

(Effect of adding saturated aqueous solution of lithium chloride to hydrophobic ionic liquid)
In Example 1, the effect of adding anhydrous LiCl was examined. In order to more efficiently incorporate LiCl into the ionic liquid, the effect of adding a saturated LiCl solution was investigated.

  As the hydrophobic ionic liquid used, three types of ionic liquids ([DMAcmim] [Tf2N], [DEAcmim] [Tf2N], [AcPEmim] [Tf2N]) containing carbonyl groups used in Example 1 were used. Toriko

  10 mg of LiCl saturated aqueous solution (19.53 mol / L, about 82.8 mass%) was added to 490 mg of each hydrophobic ionic liquid. A sample containing only 500 mg of hydrophobic ionic liquid was also prepared. 1 wt% (5 mg) of crystalline cellulose, Avicel (Sigma), was added to each sample, and the mixture was heated and stirred at 80 ° C. for 3 hours. After cooling to room temperature, 500 μl of 1 mg / ml cellulase (Tricoderma reessei-derived) aqueous solution (100 mM citrate buffer solution) was added to each sample to form a two-phase system. The saccharification reaction was performed by stirring at 40 ° C., and each sample was taken 24 hours later. In the same manner as in Example 1, derivatization with 4-aminobenzoic acid ethyl ester (ABEE) reagent and quantification of the sugar produced by HPLC analysis were performed. went. Based on the obtained glucose concentration, the conversion efficiency to sugar when the crystalline cellulose added before the reaction was taken as 100 was calculated according to the following formula.

The results of the saccharification reaction after 24 hours are shown in FIG. As shown in FIG. 4, as in Example 1, in all the hydrophobic ionic liquids containing a carbonyl group, an increase in saccharification rate was confirmed by adding lithium chloride. Compared with the type of hydrophobic ionic liquid, the addition of [DMAcmim] [Tf ₂ N] and [DEAcmim] [Tf ₂ N] to a saturated aqueous solution of lithium chloride resulted in about 60 even under relatively low processing conditions of 80 ° C. % Saccharification rate was obtained, and it was found that a saccharification rate exceeding the effect of solid lithium chloride addition was obtained. Therefore, as in Example 1, when a carbonyl group is included in the molecular structure of the ionic liquid, the structure relaxation effect of the cellulose chain can be enhanced by Cl 2 ⁻ having a high hydrogen bonding ability caused by the interaction between this and lithium chloride. Sex was suggested. It was also revealed that this effect proceeds more effectively when lithium chloride is dispersed in an aqueous solution.

(Additional effect of salt other than LiCl to hydrophobic ionic liquid)
In order to verify whether or not other salts have an effect of addition of LiCl in Example 1, the effect of addition of NaCl and KCl was examined.

In the study, a hydrophobic ionic liquid [DEAcmim] [Tf2N] containing a carbonyl group was used. [DEAcmim] [Tf2N] 980 mg was collected, and anhydrous LiCl, NaCl, and KCl were added to each so as to be 1 wt% (10 mg) to prepare 1,000 mg of hydrophobic IL. As a negative control, a sample consisting of 1,000 mg of [DEAcmim] [Tf2N] was also prepared.
To this was added 1 wt% (10 mg) of crystalline cellulose (Avicel, Sigma), and the mixture was heated and stirred at 150 ° C for 3 hours. After cooling to room temperature, 1,000 μl of a citrate buffer solution (final concentration 10 mM) containing a cellulase mixed solution was added to each sample to form a two-phase system. The saccharification reaction was carried out by stirring at 40 ° C., and each sample was taken after a certain time. The sampling sample was measured for glucose with a biosensor BF5 to calculate saccharification efficiency.

  The cellulase mixed solution was a mixture of Novozyme-Celluclast (Sigma) consisting of Treichoderma reesei ATCC26921 and Novozyme 188 (Sigma) consisting of Aspergillus niger at a ratio of 5: 1 to a final concentration of 6 FPU / g biomass. Added.

  Based on the obtained glucose concentration, the conversion efficiency to sugar when the crystalline cellulose added before the reaction was taken as 100 was calculated according to the above-described calculation formula.

  The result of the saccharification reaction is shown in FIG. From the results, no effect was observed when NaCl and KCl were added. Therefore, it was confirmed that the lithium salt is important.

(Examination of LiCl addition amount to hydrophobic ionic liquid)
In response to the LiCl addition effect in Example 1, the addition amount of LiCl was examined. In the study, a hydrophobic ionic liquid [DEAcmim] [Tf2N] containing a carbonyl group was used. [DEAcmim] [Tf2N] 1,000 to 980 mg was collected, and anhydrous LiCl was added to each so as to be 0 to 20 mg to prepare 1,000 mg of hydrophobic IL. 1 wt% (10 mg) of crystalline cellulose (Avicel) was added thereto, and the mixture was heated and stirred at 150 ° C. for 3 hours. After cooling to room temperature, 1,000 μl of a citrate buffer solution (final concentration 10 mM) containing a cellulase mixed solution was added to each sample to form a two-phase system. The saccharification reaction was performed by stirring at 40 ° C., and each sample was taken after a certain time. The sampling sample was measured for glucose with a biosensor BF5 to calculate saccharification efficiency.

  The cellulase mixed solution was a mixture of Novozyme-Celluclast (Sigma) consisting of Treichoderma reesei ATCC26921 and Novozyme 188 (Sigma) consisting of Aspergillus niger at a ratio of 5: 1 to a final concentration of 6 FPU / g biomass. Added.

  Based on the obtained glucose concentration, the conversion efficiency to sugar when the crystalline cellulose added before the reaction was taken as 100 was calculated according to the above-described calculation formula.

  The result of the saccharification reaction is shown in FIG. From the results, the effect of improving saccharification was observed even when the LiCl addition amount was 1 mg.

Claims (14)

A method for treating a cellulose-containing material,
Contacting the cellulose-containing material with a hydrophobic ionic liquid having a carbonyl group;
A processing method comprising: The said hydrophobic ionic liquid is a processing method of Claim 1 or 2 which has 1 type, or 2 or more types of cation species selected from the ionic liquid represented by the following formula | equation.
(In formulas (I) and (II), at least one substituent selected from R _{1 to} R ₄ is represented by the following formula (1). In formulas (III) and (IV), R ₁ and At least one substituent selected from R ₂ is represented by the following formula (1): In formula (V), R ₁ is represented by the following formula (1). (In (IV), the substituent not represented by the following formula (1) independently represents an optionally substituted alkyl group, alkenyl group, alkynyl group or aryl group.)
(In Formula (1), R ₅ represents an optionally substituted diyl group of a hydrocarbon, and R ₆ represents an optionally substituted alkyl group, alkenyl group, alkynyl group, and aryl group.) The method according to claim 1 or 2, wherein the cationic species is represented by the formula (2).
(In Formula (2), R ₁ and R ₆ each independently represent an alkyl group, an alkenyl group, an alkynyl group, and an aryl group, which may be substituted, and R ₅ represents an optionally substituted hydrocarbon group. Represents a diyl group.)   The anion species of the ionic liquid is one or more selected from the fluoroalkyl group-containing anion species selected from a perfluoroalkyl group-containing fluorophosphate anion and a perfluoroalkyl group-containing sulfonylimide anion. The processing method in any one of 1-3.   A step of supplying a hydrophilic solvent to the hydrophobic ionic liquid to form a two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase. Method.   Furthermore, the said hydrophobic ionic liquid is a processing method in any one of Claims 1-5 containing lithium chloride.   The processing method of Claim 6 provided with the process of adding lithium chloride or lithium chloride aqueous solution to the said hydrophobic ionic liquid prior to the said dispersion | distribution process. A method for producing a degradation product of a cellulose-containing material,
Contacting the cellulose-containing material with a hydrophobic ionic liquid phase having a carbonyl group;
Supplying a hydrophilic solvent for the hydrophobic ionic liquid to the cellulose-containing material after contact with the hydrophobic ionic liquid to form a two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase;
Decomposing cellulose of the cellulose-containing material in the vicinity of the interface between the hydrophobic ionic liquid phase and the hydrophilic solvent phase with cellulase;
A production method comprising:   The production method according to claim 6, comprising a step of recovering at least a part of the hydrophilic solvent phase after the cellulose decomposition step.   The production method according to claim 1, further comprising a step of recovering at least a part of the hydrophobic ionic liquid phase after the cellulose decomposition step. An ionic liquid composition for saccharification of cellulose,
A composition comprising a hydrophobic ionic liquid having a carbonyl group.   The composition according to claim 11, further comprising lithium chloride.   The composition according to claim 12, which is obtained by adding an aqueous lithium chloride solution to the hydrophobic ionic liquid. A method for producing useful substances,
Contacting the cellulose-containing material with a hydrophobic ionic liquid phase having a carbonyl group;
Supplying a hydrophilic solvent for the hydrophobic ionic liquid to the cellulose-containing material after contact with the hydrophobic ionic liquid to form a two-phase system of the hydrophobic ionic liquid phase and the hydrophilic solvent phase;
Decomposing cellulose of the cellulose-containing material in the vicinity of the interface between the hydrophobic ionic liquid phase and the hydrophilic solvent phase with cellulase;
A step of producing useful substances by fermentation of microorganisms using the cellulose degradation product obtained in the cellulose degradation step as a carbon source;
A production method comprising: