An α-amylase encoding gene was amplified by polymerase chain reaction from Saccharomycopsis fibuligeru and inserted into a shuttle vector YEp352,together with the yeast phosphoglycerate kinase 1 prumoter and a-factor...An α-amylase encoding gene was amplified by polymerase chain reaction from Saccharomycopsis fibuligeru and inserted into a shuttle vector YEp352,together with the yeast phosphoglycerate kinase 1 prumoter and a-factor signal gene. The recombinant expression plasmid pLA8α was transformed into an industrial strain of Saccharomycopsis cerevisiae Sc-11. The activity of the α-amylase produced by the transformant Sc-11-pLA8α was 6.3 U/mL and the starch utilization rate in YPS medium was 42%. The purified amylase was analyzed by SDS-PAGE,showing a molecular weight of 55×10^3 protein band. Furthermore, the residual sugar, ethanol and some volatile compounds in the fermented worts under simulating brewing conditions were determined by chromatographic analyses. The fermentation characteristics of Sc-ll-pLA8α were similar to that of Sc-ll and only minor changes in the concentration of flavor compounds could be observed.展开更多
基金Supported bythe National Tenth Five-Year Hi-Technique Project(2001BA708B05-04)
文摘An α-amylase encoding gene was amplified by polymerase chain reaction from Saccharomycopsis fibuligeru and inserted into a shuttle vector YEp352,together with the yeast phosphoglycerate kinase 1 prumoter and a-factor signal gene. The recombinant expression plasmid pLA8α was transformed into an industrial strain of Saccharomycopsis cerevisiae Sc-11. The activity of the α-amylase produced by the transformant Sc-11-pLA8α was 6.3 U/mL and the starch utilization rate in YPS medium was 42%. The purified amylase was analyzed by SDS-PAGE,showing a molecular weight of 55×10^3 protein band. Furthermore, the residual sugar, ethanol and some volatile compounds in the fermented worts under simulating brewing conditions were determined by chromatographic analyses. The fermentation characteristics of Sc-ll-pLA8α were similar to that of Sc-ll and only minor changes in the concentration of flavor compounds could be observed.
