Iogen Energy Corporation

Glenn D Munkvold

Jason B Edwards

Loreta Gudynaite-Savitch

Philippe J Dufresne

Jennifer Donaldson

Jan-Maarten A Geertman

Gary M Pigeau

Jan-Maarten Geertman

Lisa McMillan

Brian Foody

The present invention relates to novel xylose-fermenting yeast strains (for example, yeast of the genus, e.g.,) with an enhanced ability to ferment the xylose (and/or another pentose sugar) present in a lignocellulosic hydrolysate to a fermentation product(s) (for example, an alcohol (e.g., ethanol) or a sugar alcohol (e.g., xylitol)).

Modified yeast strains exhibiting enhanced fermentation of lignocellulosic hydrolysates

A method for obtaining a fermentation product from a sugar hydrolysate obtained from a feedstock containing hemicellulose, by (i) removing suspended fiber solids from said sugar hydrolysate to obtain a clarified sugar solution; (ii) fermenting xylose in the clarified sugar solution in a fermentation reaction with yeast to produce a fermentation broth comprising the fermentation product; (iii) separating the yeast from the fermentation broth to produce a yeast slurry; (vi) treating the yeast slurry thus obtained with an oxidant to kill microbial contaminants, thereby an oxidant-treated yeast slurry; (v) re-introducing at least a portion of the oxidant-treated yeast back to step (ii) to increase the concentration of yeast in said fermentation reaction; and (vi) recovering the fermentation product.

Method for the production of a fermentation product from a pretreated lignocellulosic feedstock

A fermentation process using hemicellulose-derived carbohydrates for the production of cellulase mixtures with a high proportion of cellulases relative to hemicellulases is provided. The cellulases produced by the process of the invention are further characterized by high specific productivity. The resulting cellulase mixtures comprise at least two times more cellulase than hemicellulase and are useful for the hydrolysis of cellulosic substrated, particularly, pretreated lignocellulosic substrate.

Method for cellulase production

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Fairchild, ME, United States of America

Glenn D Munkvold