Enzymatic conversion of hemi/cellulosic residues using novel thermostable enzymes from hyperthermophiles

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Major biomass on earth comprises trees and crops. Agricultural residues are a major type of biomass material remaining after harvesting agricultural crops and can be used for producing renewable energy sources such as ethanol. The main obstacle for bioconversion of the residues is difficulty in utilization of their virtually insoluble components, cellulose and hemicellulose, and in high efficient production of ethanol by microorganisms. It is highly desirable to use minimal pretreatment of the raw materials and achieve maximal bioconversion to renewable energy sources. Hyperthermophiles are a group of microorganisms that can grow at temperatures up to 121°C, and they possess highly thermostable enzymes, such as cellulase and xylanase, and other enzymes catalyzing further metabolic processes towards the production of ethanol, which have great potential in the application of bioconversion of agricultural as well as tree residues. It is also expected thatconversion rate of the cellulosic and hemicellulosic materials will be higher at elevated temperatures. Our long-term goal of this research is to develop a highly efficient enzymatic system for the conversion of cellulosic and hemicellulosic materials using thermostable and proficient enzymes. Our specific objectives of this proposal are: to identify and characterize novel hydrolases and key enzymes involved in pentose metabolic pathway; to enhance enzymatic activities for being used for the conversion of agricultural residues. The discovery of new types of cellulase and hemicellulase, and novel enzymes involved in pentose utilization, will help improve currently used industrial fermentation processes and provide central information for production of thermostable enzymes catalyzing the conversion of lignocellulosic materials.