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

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

摘要:

【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°C，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(-)-酒石酸的生产提供了一种新的方法。

Abstract:

[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.