从云南腾冲温泉水样中分离到1株产木糖异构酶活性较高的嗜热菌,根据菌株的形态特征和16SrD-NA序列,鉴定为Anoxybacillus flavithermus WL。采用单因素优化实验及正交设计,确定该菌株在木糖添加量15g/L、接种量3%、初始pH8.0、65℃的条件下发酵24h,达到最高酶活13.6U/mL。该菌株木糖异构酶粗酶液的最适反应温度为90℃。

A thermophilic bacterium producing xylose isomerase was isolated from Yunnan Tengchong Hot Spring water samples. The strain was finally identified as Anoxybacillus flavithermus WL based on morphological and 16S rDNA gene sequence analysis. Its optimal fermentation conditions for xylose isomerase were determined as follows:cultivation temperature 65℃,culture initial pH 8.0,inoculum density 3% and 15 g/L xylose for 24h. Under these conditions,enzyme activity reached 13.6 U/mL. Xylose isomerase from this strain performed the highest activity at 90℃.