耐酒精半纤维素降解菌的筛选、鉴定及产酶分析

从石油污染严重地区的贫瘠土壤中筛选得到的一株高产木聚糖酶且能够耐受一定浓度酒精的细菌,经生理生化实验及16SrDNA鉴定为短小芽孢杆菌(Bacillus pumilus),命名为DT83。对其产木聚糖酶的发酵条件进行优化,结果表明:最适碳源为木聚糖,最适氮源为蛋白胨,产酶最适温度为28℃,最佳初始pH值为8.5。SDS-PAGE分析表明,木聚糖酶分子量约为23kD。DT83和E.coli BL21的酒精耐受实验结果比较表明,DT83具有较高酒精耐受度,可达到8%～10%。

SCREENING, IDENTIFICATION AND ENZYMATIC ANALYSIS OF AN ALCOHOL-STABLE HEMICELLULOSE DEGRADATION BACTERIUM

A high xylanase-producing strain with a certain alcohol tolerance was screened from barren soil suffering severe petroleum pollution. According to the physiological-biochemical characteristics and 16SrDNA sequencing, the strain was identified as Bacillus pumilus and named DT83. Optimization of fermentation conditions for xylanase production revealed that the optimum carbon source was xylan, the optimum nitrogen source was peptone, the optimum enzymatic temperature was 28℃, and the initial pH was 8.5. SDS-PAGE analysis indicated that the molecular weight of the xylanase was about 23kD, which was as expected, Comparison of alcohol tolerance between DT83 and E. coli BL21 showed that DT83 has a sronger tolerance which can reach 8%-10%.