酵母基因克隆受体菌的构建

Construction of Recipient Strains for Cloning of Yeast Glucose Amylase Gene

近年来,一些国家的实验室采用酵母菌重组DNA技术将外源淀粉酶基因引入酿酒酵母中,构建成具有分解淀粉能力的工程菌株,其中酵母糖化酶基因是重要的来源之一。大部分酿酒酵母携带糖化酶基因的抑制基因(INH1),为了在酿酒酵母中克隆和表达糖化酵母糖化酶基因(STA),需要构建适宜的受体菌,其遗传标记应为trp1/leu2 sta°inh°。

The recipient strains for cloning of yeast glucose amylase gene ha-ve been constructed by means of micromanipulation technique. One ofthe segregants with auxotrophic marker (trp1), SD-4-23b (α trp1 arg4STA2 inh°), was obtained from the cross between S.cerevisiae DP-1(his1 trp1 sta° INH1) and S. diastaticus 5206-1B (a arg4 STA2 inh°).Then the segregant was hybridized with S. cerevisiae YIYD (a leu2-3,J 12 his4 lys7 sta° inh°). Eleven recipient strains (trp1 sta°inh°) deri-ved from the latter cross are suitable for the transformation of E.coli-yeast shuttle plasmid pCN60 (TRP1) and cloning of glucose amylasegene. Some of the segregants with different auxoutrophic markers andSTA2 gene which were pable of fermenting starch more rapidly werealso obtained.