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.

Description

[0001] The present application claims the benefit of U.S. Provisional Application Serial No. 60 / 452,631, filed Mar. 7, 2003, U.S. Provisional Application No. 60 / 498,098, filed Aug. 27, 2003, U.S. Provisional Application No. 60 / 502,727, filed Sep. 12, 2003, and U.S. Provisional Application No. 60 / 538,334, filed Jan. 22, 2004, the contents of which are herein incorporated by reference in their entirety.[0002] Methods to enhance the production of free sugars and oligosaccharides from plant material are provided.[0003] Plant biomass is comprised of sugars and represents the greatest source of renewable hydrocarbon on earth. However, this enormous resource is under-utilized because the sugars are locked in complex polymers. These complex polymers are often referred to collectively as lignocellulose. Sugars generated from degradation of plant biomass could provide plentiful, economically competitive feedstocks for fermentation into chemicals, plastics, and fuels, including ethanol as a su...

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Benefits of technology

0039] Physical treatments, such as grinding, boiling, freezing, milling, vacuum infiltration, and the like may also be used with the methods of the invention. A physical treatment such as milling allows a higher concentration of lignocellulose to be used in batch reactors. By "higher concentration" is intended up to about 20%, up to about 25%, up to about 30%, up to about 35%, up to about 40%, up to about 45%, or up to about 50% lignocellulose. The chemical and/or physical treatments can be administered concomitantly or sequentially with respect to the treatment methods of the invention. The lignocellulose may also be contacted with a metal ion, ultraviolet light, ozone, and the like. These treatments may enhance the effect of the chemical treatment for some materials by inducing hydroxyl radical formation. The methods of the invention can be carried out in any suitable container including vats, commercial containers, bioreactors, batch reactors, fermentation tanks or vessels. During the treatment of the invention, the reaction mixture may be agitated or stirred.

0040] The methods of the invention improve the efficiency of biomass conversion to simple sugars and oligosaccharides. Efficient biomass conversion will reduce the costs of sugars that can then be converted to useful fermentation based products. By "fermentation-based product" is intended a product produced by chemical conversion or fermentation. Such products include, but are not limited to, specialty chemicals, chemical feedstocks, plastics, solvents and fuels. Specific products that may be produced by the methods of the invention include, but not l

Problems solved by technology

However, this enormous resource is under-utilized because the sugars are locked in complex polymers.

However corn grain is expensive, and has other high value uses, such as use in livestock feeds, and high fructose corn syrups (Wyman, ed.

In contrast, the carbohydrates comprising lignocellulosic materials such as corn stover are more diffi

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