Abstract Chlorothalonil, a commonly used chlorinated benzonitrile fungicide, is often detected in various environments, including marine ecosystems, and poses a threat to human health and environmental safety. Although the biodegradation of chlorothalonil via several catabolic pathways has been reported by various kinds of microorganisms, the degradation of chlorothalonil by marine strains, as well as their special catabolic pathways, remain to be studied. In this study, six strains of chlorothalonil-degrading bacteria (Sulfitobacter sp. S-1, Sphingobium sp. P-1, Marinicauda sp. M-1, Erythrobacter sp. E-17, Stakelama sp. P-2 and Oceanicaulis sp. B-1) were screened and characterized from a total of 110 culturable bacterial strains obtained from the surface seawater of the Northwestern Pacific. Sphingobium sp. P-1, showing the highest degrading efficiency among the six degraders, and was thus selected for further investigation. Strain P-1 completely removed 20 mg L−1 of chlorothalonil from mineral salt-carbon medium within 24 h and from seawater within 3 d. During the degradation of chlorothalonil by strain P-1, two metabolites (4-sulfydryl-2,5,6-trichloroisophthalonitrile and 5-cyano-4,6,7-trichloro-2H-1,2-benzisothiazol-3-one) were detected and identified by liquid chromatography–mass spectrometry that suggest a special catabolic pathway of chlorothalonil via thiolation and nitrile hydration in the marine strain P-1.

中文翻译：

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从西北太平洋表层海水中分离的海洋菌株通过硫醇化和腈水合降解百菌清

摘要 百菌清是一种常用的氯化苄腈类杀菌剂，经常在包括海洋生态系统在内的各种环境中被检测到，对人类健康和环境安全构成威胁。尽管已有多种微生物报道了通过多种分解代谢途径降解百菌清，但海洋菌株对百菌清的降解及其特殊的分解代谢途径仍有待研究。在这项研究中，六株百菌清降解菌（亚硫酸杆菌属 S-1、鞘氨醇属 P-1、海藻属 M-1、红杆菌属 E-17、Stakeleama sp. P-2 和 Oceanicaulis sp.。 B-1) 是从从西北太平洋表层海水中获得的总共 110 种可培养细菌菌株中筛选和表征的。鞘氨醇菌 P-1, 在六种降解剂中显示出最高的降解效率，因此被选中进行进一步研究。菌株 P-1 在 24 小时内从矿物盐 - 碳介质中完全去除了 20 mg L-1 百菌清，在 3 天内从海水中完全去除。在菌株 P-1 降解百菌清的过程中，两种代谢物（4-巯基-2,5,6-三氯间苯二甲腈和 5-氰基-4,6,7-三氯-2H-1,2-苯并异噻唑-3-one）通过液相色谱-质谱法检测和鉴定了百菌清通过硫醇化和腈水合在海洋菌株 P-1 中的特殊分解代谢途径。