Study On Temperature Oscillation Fermentation In Production Of Xylanase By Aspergillus NigerA-25

Xylanase is the enzyme family that dehydrates xylan into xylose oroligoxylose.Xlyanase has extensive applications in the industries of feed,food,fabric and papermaking,and has become one of the hot spots of modem enzymology.In the study of Xylanase,low activity of the enzyme is a main question,xylanase production main dependence microorganism's fermentation,in microorganism's fermentative process,the people discovered that the growth temperature of microorganism,is often inconsistent with the temperature of fermentation,the temperature oscillation fermentation is helpful to its metabolitesynthesis.This article study on temperature oscillation fermentation in production of xylanase,and has obtained the very good result,The main content and result of the study were as following:Aspergillus nigerA-25 growth in different temperature,through measured its biomass,knew that the best growth temperature of growth is 33℃.but uses the different fermentation temperature to carry on the experiment of Xylanase by aspergillus nigerA-25,discovered its best temperature of fermentation is 29℃.A temperature oscillatory operation with a temperature of 33℃for the early 48 hours and of 29℃for the later could shorten the cultivation time by about 8 hours incomparison with that of 29℃for all the time.The Xylanase activity is as high as 721U/ml were enhanced respectively 110 U/ml as compared with that at conwentional 29℃.we discuss the reason by the Xylanase activity analysis of percell and zymogram analysis and gene expression analysis,The results showed that temperature oscillation fermentation can increase the cell growth and the xylanase activity.The expression of xynⅢwere increased,as determined by zymogram analysisand gene expression analysis.