高产木糖醇酵母菌的筛选与鉴定

The Screening and Identification of High Yield Xylitol Yeast

为了获得1株高效转化木糖为木糖醇的酵母菌株,利用从土壤中筛选的酵母菌株转化玉米芯水解液生产木糖醇,经HPLC测得木糖醇产量,对筛选的具有产木糖醇能力的酵母菌株DQ11进行形态学的初步鉴定及26S rDNA序列分析,并以序列同源性为基础构建相关属种的系统发育树。结果表明,该菌株发酵48 h后木糖醇产量为3.34 g/L。同源性分析结果表明,分离株DQ11与季也蒙毕赤酵母菌处于同一进化分支中,相似性达99%以上,因此将筛选的高产木糖醇分离株DQ11鉴定为季也蒙毕赤酵母菌。

In order to obtain a yeast strain that can highly produce xylitol, xylitol from corn cob hydrolysate which is transformed by yeast strain screened from the soil is produced. It is measured that the yield of xylitol by HPLC, and made initial morphologic and 26S rDNA sequence analyses of screened yeast strain DQll that can produce xylitol, and built phylogenetic tree of correlative generic species on the basis of sequence homology. The result shows this yeast strain produces 3.34 g/L of xyolitol after 48 hours＇ fermentation. The result of homology analysis shows that the isolated strain DQ11 is in the same evolutionary branch with Pichia guilliermondii with a similarity of over 99%. So DQll is identified as Pichia guilliermondii.