论文部分内容阅读
利用同时表达α-淀粉酶与糖化酶基因的工业多倍体重组酵母,实现从木薯原料到乙醇的直接有效转化.两种淀粉酶基因分别从米曲霉和黑曲霉通过RT-PCR获得,连入表达载体pScIKP后通过电击转化重组进酿酒酵母AS2.489的基因组.重组菌株培养上清的α-淀粉酶活性与糖化酶活性分别达1 940 U/mL与15.5 U/mL.模拟工业上乙醇发酵条件,于5 L发酵罐中对200 g/L木薯进行直接发酵,4d内发酵液中乙醇体积分数达8.68%,约为理论值的80.9%.结果表明,所获重组酵母发酵性能优越,在不添加任何商业酶且无需预处理的条件下对木薯的直接发酵效果良好.
The direct and efficient transformation from cassava raw material to ethanol was achieved using an industrial polyploid recombinant yeast expressing both alpha-amylase and glucoamylase genes.The two amylase genes were obtained from Aspergillus oryzae and Aspergillus niger respectively by RT-PCR, The expression vector pScIKP was transformed into the genome of Saccharomyces cerevisiae AS2.489 by electroporation.The α-amylase activity and glucoamylase activity of the recombinant supernatant reached 1 940 U / mL and 15.5 U / mL, respectively.The simulated industrial ethanol fermentation Under the conditions, 200 g / L cassava was directly fermented in 5 L fermentor, the volume fraction of ethanol in fermentation broth reached 8.68% in 4 days, which was about 80.9% of the theoretical value.The results showed that the obtained recombinant yeast had excellent fermentation performance, The direct fermentation of cassava works well without adding any commercial enzyme and without pretreatment.