(490x) Enzyme Systems for Optimization of Ionic-Liquid Pretreated Biomass Saccharification

Biomass, which consists of cellulose, hemicellulose, and lignin, is being developed as a renewable carbon source for fuel and chemical production. The use of biomass as a renewable carbon source requires that it be hydrolyzed to monomeric sugars through efficient processes. The process which shows the most promise for the deconstruction of biomass is pretreatment via chemical processes followed by enzymatic hydrolysis. Enzymatic hydrolysis is preferred over mineral acid catalyzed hydrolysis because no sugar breakdown products, which often times act as inhibitors in downstream processes, are produced.

The continued optimization of the biofuel production from terrestrial biomass includes development of processes that takes advantage of fundamental understanding of the complex interplay between lignocellulose components. Ionic liquid (IL) pretreated biomass provides an opportunity to improve hydrolysis processes through increased understanding of the interactions between lignocellulosic components since it is a unique feedstock in that it provides amorphous cellulose while retaining the hemicellulose and lignin components. In addition, enzyme groups (cellulases and hemicellulases) which are critical for saccharification of this substrate are indentified. Some of these enzyme groups are endoglucanases, cellobiohydrolases, β-glucosidases, xylanases, and xylosidases. Selected cellulases and hemicellulases are expressed, isolated, purified and characterized for activity and substrate specificity. The identified enzyme systems are also examined for their synergistic effects on the hydrolysis of ionic liquid pretreated biomass.