Methods to enhance the activity of lignocellulose-degrading enzymes

Abstract

Methods for hydrolyzing lignocellulose are provided, comprising contacting the lignocellulose with at least one chemical treatment. Methods for pretreating a lignocellulosic material comprising contacting the material with at least one chemical are also provided. Methods for liberating a substance such as an enzyme, a pharmaceutical, or a nutraceutical from plant material are also provided. These methods are more efficient, more economical, and less toxic than current methods.

1 . A method for hydrolyzing lignocellulose, comprising contacting said lignocellulose with at least one chemical under moderate conditions to generate a treated lignocellulose, and contacting said treated lignocellulose with at least one enzyme capable of hydrolyzing lignocellulose, wherein said chemical is selected from the group consisting of oxidizing agents, denaturants, detergents, organic solvents, bases, and combinations thereof, wherein said moderate conditions comprise: 
 a) a temperature from about 10° C. to about 90° C.;    b) a pressure less than about 2 atm; and,    c) a pH between about pH 4.0 and about pH 10.0.    
     
     
         2 .- 3 . (Cancelled)  
     
     
         4 . The method of  claim 1 , wherein said chemical comprises an oxidizing agent selected from the group consisting of hydrogen peroxide, urea hydrogen peroxide, benzoyl peroxide, a superoxide, potassium superoxide, a hypochlorite, hypochlorous acid, chlorine, nitric acid, a peroxyacid, peroxyacetic acid, a persulfate, a percarbonate, a permanganate, osmium tetraoxide, chromium oxide, and sodium dodecylbenzenesulfonate.  
     
     
         5 . The method of  claim 1 , wherein said chemical comprises an organic solvent.  
     
     
         6 . The method of  claim 1 , wherein said chemical comprises a denaturant.  
     
     
         7 . The method of  claim 1 , wherein said chemical comprises a detergent.  
     
     
         8 . The method of  claim 1 , wherein said chemical comprises a base.  
     
     
         9 . The method of  claim 1 , further comprising subjecting said lignocellulose to at least one physical treatment selected from the group consisting of grinding, milling, boiling, freezing, and vacuum filtration.  
     
     
         10 . The method of  claim 1 , wherein said moderate conditions comprise a temperature of about 80° C.  
     
     
         11 . The method of  claim 1 , wherein said moderate conditions comprise a pH of about pH 5.0.  
     
     
         12 . The method of  claim 1 , wherein said contact occurs for about 24 hours.  
     
     
         13 . The method of  claim 1 , wherein said enzyme comprises at least one enzyme selected from the group consisting of cellulase, xylanase, ligninase, amylase, glucuronidase, protease, lipase, and glucuronidase.  
     
     
         14 . The method of  claim 1 , wherein said temperature is adjusted to be optimal for said enzyme prior to enzyme addition.  
     
     
         15 . The method of  claim 1 , wherein said pH is adjusted to be optimal for said enzyme prior to enzyme addition.  
     
     
         16 . The method of  claim 1 , wherein said chemical is removed prior to addition of said enzyme.  
     
     
         17 . The method of  claim 1 , further comprising removal of said chemical from said treated lignocellulose prior to additional treatment to obtain a recycled chemical.  
     
     
         18 . The method of  claim 1 , wherein contacting said lignocellulose with at least one chemical occurs simultaneously with contacting said lignocellulose with at least one enzyme capable of hydrolyzing lignocellulose.  
     
     
         19 . The method of  claim 1 , further comprising the addition of at least one fermenting organism, wherein said method results in the production of at least one fermentation-based product.  
     
     
         20 . The method of  claim 19 , wherein said product is selected from the group consisting of lactic acid, a fuel, an organic acid, an industrial enzyme, a pharmaceutical, and an amino acid.  
     
     
         21 . A method for pretreating a lignocellulosic material comprising contacting said material with at least one chemical under moderate conditions to generate a treated lignocellulose, wherein said chemical is selected from the group consisting of oxidizing agents, denaturants, detergents, organic solvents, bases, and a combination thereof wherein said moderate conditions comprise: 
 a) a temperature from about 10° C. to about 90° C.;    b) a pressure less than about 2 atm; and, c) a pH between about pH 4.0 and about pH 10.0.    
     
     
         22 . A method for liberating a substance from plant material, comprising contacting said plant material with at least one chemical under the following conditions: 
 a) a temperature from about 10° C. to about 90° C.;    b) a pressure less than about 2 atm; and,    c) a pH between about pH 4.0 and about pH 10.0,    to generate a treated plant material, wherein said chemical is selected from the group consisting of oxidizing agents, denaturants, detergents, organic solvents, bases, and a combination thereof.    
     
     
         23 . The method of  claim 22 , further comprising contacting said treated plant material with at least one enzyme capable of hydrolyzing lignocellulose.  
     
     
         24 . The method of  claim 23 , wherein said plant material comprises at least one enzyme capable of hydrolyzing lignocellulose.  
     
     
         25 . The method of  claim 24 , wherein said plant material comprises at least one plant that has been genetically engineered to express at least one enzyme capable of hydrolyzing lignocellulose.  
     
     
         26 . The method of  claim 25 , comprising incubating said plant material under conditions that allow expression of said enzyme capable of hydrolyzing lignocellulose prior to contacting said plant material with said chemical.  
     
     
         27 . The method of  claim 22 , wherein said substance is selected from the group consisting of an enzyme, a pharmaceutical, and a nutraceutical.  
     
     
         28 . The method of  claim 27 , wherein said plant material comprises at least one plant that has been genetically engineered to express said substance.  
     
     
         29 . A method for hydrolyzing lignocellulose, comprising contacting said lignocellulose with at least one chemical to generate a treated lignocellulose, and contacting said treated lignocellulose with at least one enzyme capable of hydrolyzing lignocellulose, wherein said chemical is an oxidizing agent selected from the group consisting of a hypochlorite, hypochlorous acid, chlorine, nitric acid, a peroxyacid, peroxyacetic acid, a persulfate, a percarbonate, a permanganate, osmium tetraoxide, chromium oxide, sodium dodecylbenzenesulfonate, and a compound capable of generating oxygen radicals.  
     
     
         30 . A method for hydrolyzing lignocellulose, comprising contacting said lignocellulose with a base at a pH of about 9.0 to about 14.0 to generate a treated lignocellulose, and contacting said treated lignocellulose with at least one enzyme capable of hydrolyzing lignocellulose.  
     
     
         31 . The method of  claim 30 , wherein said base is sodium carbonate or potassium hydroxide.