产顺式环氧琥珀酸水解酶的博德特氏菌BK-52的筛选、鉴定及其产酶条件优化

目的]产顺式环氧琥珀酸水解酶(CESH)新型菌株的筛选、鉴定及其产酶条件优化.方法]通过电镜、Biolog GN、(G C)含量和16S rDNA序列研究,对筛选菌株进行分类鉴定.通过红外光谱、核磁共振氢谱和碳谱、质谱以及旋光度实验,鉴定纯化产物的结构并优化CESH产酶条件.结果]本文筛选出一株产CESH的新型菌株,该菌株可将顺式琥珀酸盐转化为D(-)-酒石酸,属于博德特氏菌属,并将其命名为博德特氏菌BK-52.最佳发酵条件为:最佳温度30℃,最佳pH7.0,最佳发酵时间36 h,最佳碳源蔗糖,最佳无机氮源硫酸铵,最佳酶诱导剂顺式环氧琥珀酸二钠.在此最佳条件下,CESH酶活最高达764 U/g生物量.结论]本文筛选的新菌株博德特氏菌BK-52为D(一)一酒石酸的生产提供了一种新的方法.

Isolation and identification of a novel cis-epoxysuccinate hydrolase- producing Bordetella sp. BK-52 and optimization of enzyme production

Objective] To isolate and identify a novel strain with cis-epoxysuccinate hydrolase (CESH) activity and to optimize its enzyme production. Methods] The isolated strain was identified by electron microscopy, Biolog gram negative (GN) test, G+C (guanine plus cytosine) content measurement and 16S rDNA sequence. The purified enzymatic biotransformed product was identified by IR, 1H-NMR, 13C-NMR, MS and optical rotation analysis. Then the fermentation conditions for CESH production were optimized. Results] A novel CESH-producing strain was isolated for biotransforming cis-epoxysuccinate to D(-)-tartaric acid. It was assigned to genus Bordetella and named Bordetella sp. BK-52. The optimal conditions were found to be 30°C, pH 7.0, fermentation time 36 h, car-bon source of saccharose, inorganic nitrogen source of ammonium sulfate and enzyme inducer of disodium cis-epoxysuccinate. Under these conditions, the maximum CESH activity reached 764 U/g biomass. Conclusion] The isolated Bordetella sp. BK-52 provided a new alternative for biosynthesis of D(-)-tartaric acid from cis-epoxysuccinate.