菌株Pigmentiphaga sp.H8对3,5-二溴-4-羟基苯甲酸的降解及脱溴机制

溴代化合物不仅是一类重要的环境污染物，而且是海洋环境中自发产生的一类物质，溴代化合物的微生物脱溴研究是国内外关注的热点。本研究小组前期筛选到一株3,5-二溴-4-羟基苯甲酸（DBHB）的脱溴菌株Pigmentiphaga sp. H8，研究发现其脱溴产物不同于以往报道的产物，暗示存在新的脱溴途径和脱溴机制。本项目以好氧菌株H8为研究对象，揭示其降解DBHB的完整代谢途径；克隆DBHB的降解基因（簇），尤其是脱溴酶基因；并阐明脱溴酶的催化机制。本项目的研究不仅能丰富溴代芳烃类化合物的微生物脱溴机制，为此类化合物的生物降解和污染修复提供技术支持，而且为研究海洋生态系统的卤素循环提供一定的理论基础。

Brominated compounds are important environmental pollutants. In addition, brominated compounds are reported to be naturally produced in marine environment. In recently years, microbial debromination of brominated compounds becomes one of hot research topics among scientific research community. In our previous study, a bacterial strain named Pigmentiphaga sp. H8, which was capable of debrominating 3,5-dibromo-4-hydroxybenzoate (DBHB), was isolated. It was found that the debrominated metabolites were totally different from previously reported ones, indicating that novel debromination pathway and debromination mechanism exist. In this proposed project, we will emphasize on the study of the complete metabolic pathway of DBHB in strain H8, clone of the complete degrading gene (cluster), especially the debromination gene, involved in the metabolism of DBHB; and the illumination of the catalytic mechanism of debromination enzyme. The outcomes of this project will broaden the microbial debromination mechanism of brominated aromatics, provide technical support for biodegradation and bioremediation of brominated aromatic contaminated sites, and in some extent, provide theoretical foundation of the halogen cycle in marine ecosystem.