Wang Hongyan, Jin Huijuan, Wang Jingjing, Wang Xin, Li Xiuying, Yan Jun, Yang Yi
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China.
University of Chinese Academy of Sciences, Beijing 100049,China.
Environ Sci Technol. 2025 Jan 14;59(1):779-790. doi: 10.1021/acs.est.4c08999. Epub 2024 Dec 26.
Organohalide-respiring bacteria (OHRB) have been found in various environments and play an indispensable role in the biogeochemical cycling and detoxification of halogenated organic compounds (HOCs). Currently, few ORHB have been reported to perform reductive dechlorination under high salinity conditions, indicating a knowledge gap on the diversity of OHRB and the survival strategy of OHRB in saline environments (e.g., estuarine, marine). This study reports the characterization of an enrichment culture dominated by a new population strain W derived from estuarine sediments, which demonstrates the capability to dechlorinate 1,2-dichloroethane (1,2-DCA) to ethene under elevated salinity (≥5.1% NaCl, w/v). Metagenomic and proteomic analyses revealed that the distinctive high-salinity dechlorination of strain W is primarily attributed to a putative reductive dehalogenase (RDase) DdeA, which shares >91.4% amino acid identity with the dihaloeliminating RDase DcpA from other strains. Additionally, ectoine biosynthesis enzymes (EctABC) contribute to the strain's salt tolerance. These findings underscore the potential of OHRB, particularly , to detoxify HOCs in high-salinity environments, such as estuarine and marine ecosystems, by employing compatible solutes as an adaptive mechanism.
在各种环境中都发现了有机卤呼吸细菌（OHRB），它们在卤代有机化合物（HOCs）的生物地球化学循环和解毒过程中发挥着不可或缺的作用。目前，据报道很少有OHRB能在高盐条件下进行还原脱氯，这表明在OHRB的多样性以及OHRB在盐环境（如河口、海洋）中的生存策略方面存在知识空白。本研究报告了一种以源自河口沉积物的新种群菌株W为主的富集培养物的特性，该菌株在盐度升高（≥5.1% NaCl，w/v）的条件下能够将1,2 - 二氯乙烷（1,2 - DCA）脱氯为乙烯。宏基因组和蛋白质组分析表明，菌株W独特的高盐脱氯作用主要归因于一种假定的还原脱卤酶（RDase）DdeA，它与其他菌株的二卤消除RDase DcpA的氨基酸同一性>91.4%。此外，四氢嘧啶生物合成酶（EctABC）有助于该菌株的耐盐性。这些发现强调了OHRB，特别是通过利用相容性溶质作为一种适应机制，在河口和海洋生态系统等高盐环境中对HOCs进行解毒的潜力。
