Isolation Of Xylose Fermentation Yeast And Research On Its Characteristic

With the rapidly development of economy,there is a lack of mineral resource of sorts day by day.Energy sources scarcity threastened the continuable development of society.The importance of alternative energy sources gave birth to initiatives.Fuel ethanol is regarded as one of the most promising environmentally friendly renewable recosource.Expansion of production of bioethanol utilizing lower-value lignocellulose offers a great potential for not only reducing the production cost but also protecting the environment as it produces far less air pollutants than gasline.D-Xylose is the most abundant monosaccharide in lignocellulose hydrolysate after glucose.Consequently, ethanolic fermentation of xylose is of major concem for the efficient utilization of lignocellulosic hydrolysates to produce fuel ethanol. Therefore, to obtain a bacterial strain that can largely use xylose to produce ethanol is always a hot topic within this area.This study was based on microbiology theory. According to habitation of xylose zymogenic, a bacterium, which can ferment xylose to produce ethanol , was filtered from natural environment. It was identified by analyzing its physiological and biochemical characteristics and applying several molecule biological means. It was domesticated by means of its zymolytic characteristic, in order to improve its ability of zymolysis. Then the parameters of technique of fermenting xylose to produce ethanol were optimized, to lay a foundation of the cellulase to the alcohol production technique. The main content of this research is as follows.Using the flat band method of YEPD, we screened 70 strains of alcohol producing yeasts from the soil which contains rich of rotted cellulose. In still, aerobic and anaerobic conditions, the 70 strains of yeasts fermented xylose. Based on the volume of production of alcohol, we screened a strain out of the 70s, which was named FL20-2. FL20-2 fermented xylose and glucose, and produced alcohol at the same time. In anaerobic condition, the maximum of volume of alcohol was 6.12g per 100g xylose, which was the 13.3 percent of the theoretical yield. According to the morphologic specificity and physiological-biochemical...