Ionic liquid-tolerant cellulase enzymes
The present invention provides ionic liquid-tolerant cellulases and method of producing and using such cellulases. The cellulases of the invention are useful in saccharification reactions using ionic liquid treated biomass.
1. A composition comprising (i) an isolated ionic liquid-tolerant cellulase having β-glucosidase activity and comprising an amino acid sequence having at least 95% sequence identity to the amino acid sequence of SEQ ID NO:4; and (ii) an ionic liquid, wherein the ionic liquid has an imidazolium cation.
2. The composition of claim 1 , wherein the ionic liquid-tolerant cellulase comprises an amino acid sequence having at least 98% sequence identity to the amino acid sequence of SEQ ID NO:4.
3. The composition of claim 1 , further comprising a lignocellulosic biomass.
4. The composition of claim 1 , wherein the ionic liquid-tolerant cellulase comprises the amino acid sequence of SEQ ID NO:4.
5. A method of increasing the yield of soluble sugar from a lignocellulosic biomass, the method comprising incubating lignocellulosic biomass with a composition comprising an ionic liquid-tolerant cellulase and an ionic liquid having an imidazolium cation in an enzymatic hydrolysis reaction, wherein the ionic liquid-tolerant cellulase has β-glucosidase activity and comprises an amino acid sequence having at least 95% sequence identity to the amino acid sequence of SEQ ID NO:4.
6. The method of claim 5 , wherein the ionic liquid-tolerant cellulase has at least 98% sequence identity to the amino acid sequence of SEQ ID NO:4.
7. The method of claim 5 , wherein the lignocellulosic biomass is pretreated with ionic liquid.
8. The composition of claim 1 , wherein the ionic liquid is 1-ethyl-3-methyl-imidazolium acetate ([C 2 mim][OAc]).
9. The method of claim 5 , wherein the ionic liquid-tolerant cellulase comprises the amino acid sequence of SEQ ID NO:4.
10. The method of claim 5 , wherein the ionic liquid is [C 2 mim][OAc].