带有木糖还原酶基因和木糖醇脱氢酶基因的重组酿酒酵母的构建

采用双载体系统，将携带有瑞氏木霉木糖醇脱氢酶基因的表达质粒pAJ401－Xdh1转化已带有树干毕赤氏酵母木糖还原酶基因的重组酿酒酵母H475，构建了同时带有毕赤氏酵母木糖还原酶基因和瑞氏木霉木糖醇脱氢酶基因的重组酿酒酵母HX1。研究了重组酿酒酵母HX1对木糖的转化利用情况。

CONSTRUCTION OF RECOMBINANT S. CEREVISIAE HARBOURING BOTH XYLOSE REDUCTASE AND XYLITOL DEHYDROGENASE GENES

Using two vectors-system, the recombinant S cerevisiae stain HX1 harboring both xr from Pichia stipitis and xdhl from Trichoderma reesei was consented by transformation of Plasmid pAJ401-xdh1harbowring T reesei xdh gene into recombinant S. cerevisiae strain H475 harbouring P. stipitis xr gene. The utilization and conversion of xylose by thes recombinant strain HX1 wered studied. The satrin HX1 was able to grow on the medium with xylose as the sole carbon source. When grew in 1.8% xylose in shake flasks at 30℃,S cerevisiae HX1 was able to convert more than 90% of the xylose into xylitol, ethanol and other products.The conversion efficiency Of xylose into xylitol was 56～66% and 0.9g/L ethanol prodwtion was obtained. The situations of HX1 grown on the medium in which 1.8% xylose + 0.2% glucose as carbon sources wered studied also.