【摘要】 从强絮凝酿酒酵母 (Saccharomycescerevisiae)ABXL 1D菌株中用PCR方法扩增到絮凝基因 (Flocculationgene,FLO1) ,构建以絮凝基因作选择标记的酿酒酵母表达载体。用该载体表达Bacilluspolymyxa的 β 葡萄糖苷酶基因 ,转化子可直接从沉淀中筛选。摇瓶培养细胞得到的 β 葡萄糖苷酶比活力为 3.91u mg蛋白。在发酵葡萄糖和纤维二糖混合底物时 ,转化子的葡萄糖残存量明显低于受体菌。这将有利于利用纤维素发酵生产酒精。更多还原

【Abstract】 Selective markers used in yeast vector for gene manipulation were usually drug resistance or autotrophy. Unfortunately, drug resistance selective marker requires drug sensitive host and most industrial strains were not autotrophy. In this paper, flocculation gene (FLO1) from Saccharomyces cerevisiae ABXL 1D was amplified by PCR, sequenced and cloned to construct an expression vector. The new vector was easy to manipulate and suitable for broad host of yeasts without either autotrophy or drugs. β glucosidase gene from Bacillus polymyxa was cloned with the vector and expressed in Saccharomyces cerevisiae. The specific activity of β glucosidase of the recombinant yeast cell free extract was 3.91u/mg protein. The residue glucose of the recombinant yeast was considerably reduced in mixed fermentation of glucose and cellobiose. It should be favorable for ethanol fermentation when utilize lignocellulosic biomass as raw material.更多还原