Organohalide-respiring bacteria (OHRB) play a key role in facilitating the detoxification of halogenated organics, but their slow growth and harsh growth conditions often limit their application in field remediation. In this study, we investigated the metabolic performance and organohalide respiration process of a non-obligate OHRB, Pseudomonas sp. CP-1, demonstrating favorable anaerobic reductive dechlorination ability of 2,4,6-trichlorophenol to 4-chlorophenol with a removal rate constant (k) of 0.46 d-1. Due to its facultative anaerobic nature, strain CP-1 exhibited unique metabolic properties. In aerobic conditions, strain CP-1 preferentially utilized oxygen for rapid proliferation, and anaerobic reductive dechlorination was initiated once the oxygen was depleted. The aerobic proliferation facilitated the subsequent reductive dechlorination process. Through multi-tool analysis, a modified tricarboxylic acid cycle was proposed to be linked to organohalide respiration when acetate served as the sole carbon source. A predictive model for the electron transport chain (ETC) for reductive dechlorination was constructed, with complex Ⅰ, complex Ⅱ, ubiquinone, complex Fix (flavoprotein), and reductive dehalogenase (RDase) as the major components. A specific RDase facilitating reductive dechlorination was identified. It shared a 64.35 % amino acid similarity with biochemically characterized RDases and was designated CprA-2. Its ortho-dechlorination catalytic process was proposed through molecular docking. The discovery of highly adaptable Pseudomonas with favorable dechlorination activity and the elucidation of its metabolic properties provide valuable insights into the understanding of non-obligate OHRBs and their application regulation.

中文翻译：

---

假单胞菌如何进行 2,4,6-三氯苯酚的还原脱氯：了解代谢性能和有机卤化物呼吸过程


有机卤化物呼吸细菌 （OHRB） 在促进卤代有机物的解毒方面起着关键作用，但它们的缓慢生长和恶劣的生长条件往往限制了它们在田间修复中的应用。在这项研究中，我们研究了非专性 OHRB Pseudomonas sp. CP-1 的代谢性能和有机卤化物呼吸过程，证明了 2,4,6-三氯苯酚对 4-氯苯酚具有良好的厌氧还原脱氯能力，去除速率常数 （k） 为 0.46 d-1。由于其兼性厌氧性质，菌株 CP-1 表现出独特的代谢特性。在好氧条件下，菌株 CP-1 优先利用氧气进行快速增殖，一旦氧气耗尽，就会开始厌氧还原脱氯。好氧增殖促进了随后的还原脱氯过程。通过多工具分析，当乙酸盐作为唯一的碳源时，提出了一种改进的三羧酸循环与有机卤化物呼吸有关。构建了以复合物 I.、复合物 II.、泛醌、复合物 Fix （黄素蛋白） 和还原脱卤酶 （RDase） 为主要成分的还原脱氯电子传递链 （ETC） 预测模型。鉴定出一种促进还原脱氯的特异性 RDase。它与生化特征的 RDase 具有 64.35% 的氨基酸相似性，并被命名为 CprA-2。其邻位脱氯催化工艺是通过分子对接提出的。具有良好脱氯活性的高适应性假单胞菌的发现及其代谢特性的阐明为理解非专性 OHRBs 及其应用调节提供了有价值的见解。