(623a) Expression of Novel Enzymes for Biomass Conversion in E.Coli

With in the next generation a major world energy source, conventional crude oil, will be exhausted. Sources of natural renewable energy are being explored. Ethanol derived from biomass is one such alternative to petroleum products. Ethanol from biomass will generate economic development, provide environmental benefits and enhance national security. The Ammonia Fiber Explosion (AFEX) is a leading pretreatment process through which agricultural biomass could be pretreated followed by enzymatic hydrolysis to produce free sugars, followed by fermenting the sugars to ethanol using microbes. Significant cost reductions are still required to make biomass ethanol competitive with petroleum-derived fuels. Enzyme cost reduction for specific pretreatments is one particular cost area requiring effort.

Commercial enzymes available in the market are not tailor made for conversion of AFEX-treated biomass. These lack some important enzyme components and/or the relative ratios of enzymes are inadequate for complete cellulose and hemicellulose conversions. We report here the use of additional hydrolytic enzymes [eg, endoglucanase I (EGI), b-glucosidase, cellobiohydrolases I and II (CBH I & II), xylanase, xylobiase etc.] from different bacterial and fungal sources as well as non-hydrolytic enzymes like expansins along with commercial enzymes to enhance the conversion of AFEX-treated materials. These supplemental enzymes are expressed in E. coli. Our objective is more rapid biomass hydrolysis at high yields with lower total enzyme loadings to improve the economics of ethanol production.