Study On Screening Cellulose-Decomposing Strain And Fuel Ethanol By Biological Technology

The enerGray problem in today’s world is one of the most concerned issues, along with the whole world population growth and economic rapid development, the world demand for enerGray is more and more high. However, as the main source of enerGray and fossil enerGray is facing a depleted condition, therefore the search for a sustainable renewable enerGray has become the States to solve the problem of enerGray focus. Straw is the world’s most abundant resources, the use of biological technoloGray transformation stalk as fuel ethanol, has broad prospects for development. In this paper, the optimization of high-yield cellulase strains breeding of strains producing cellulase and simultaneous saccharification and fermentation conditions for ethanol production by process parameters optimization and other aspects were studied, the results are as follows:With Congo red staining identification and fermentation culture of isolated and screened from2strains of high-yield cellulase Penicillium strains A2and A6, on its enzyme production conditions for research. The results show that, A2and A6carboxymethyl cellulase activity were280.14247.58U; A2optimal fermentation conditions for inoculation volume15%(V/V), the initial pH5,120h, adding certain amount of Mn2+and Ca2+into the culture medium of enzyme activity were increased by10.56%and7.95%, joining the Fe2+and Hg2+on the enzyme activity is inhibited; A6best fermentation conditions for inoculation volume15%(V/V), the initial pH5,96h, adding certain amount of Mn2+into the medium enzyme activity increased13.1%, and the accession to the Ca2+, Fe2+and Hg2+on enzyme activity has certain inhibition.Based on the initial strain A2by UV and gamma ray compound mutation, a strain is the mutant strain A2-19-27, the carboxymethyl cellulase activity for351.71U, relative to the initial strain A2increased by25.55%, and genetic stability. The cellulase producing conditions are optimized, the best fermentation conditions, namely:the culture time6D, A2-19-27inoculation amount18%, medium initial pH was5, adding metal ion Mn2+. The A2-19-27cellulase activity was increased by13.34%than that before optimization.Through single factor test and orthogonal test, the ethanol production by simultaneous saccharification and fermentation the optimum process parameters, namely, the fermentation time is3D, fermentation temperature36C, yeast inoculation was8%, for9g substrate quality. Strains optimization of ethanol fermentation, ethanol yield of up to0.285g/g.