State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of the Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
Environ Pollut. 2024 Nov 15;361:124825. doi: 10.1016/j.envpol.2024.124825. Epub 2024 Aug 26.
Tris(2-chloroethyl) phosphate (TCEP) is of growing public concern worldwide because of its ubiquitous contamination, toxicity, and persistence. In this study, we investigated bacterial communities in aerobic enrichment cultures with TCEP and its two major transformation products bis(2-chloroethyl) phosphate (BCEP) and 2-chloroethanol (2-CE) as the sole carbon source. Burkholderiales and Rhizobiales were likely two main bacterial guilds involved in the hydrolysis of TCEP, while Rhizobiales and Sphingomonadales may play an important role in the hydrolysis of BCEP, given the increase of Rhizobiales and Sphingomonadales-related phosphoesterase genes when the carbon source was switched from TCEP to BCEP. All Burkholderiales, Rhizobiales, Sphingomonadales were probably efficient in 2-CE metabolism, because their dehydrogenase genes and dehalogenase genes increased after 2-CE enrichment. The different substrate preference of different bacterial guilds highlighted the importance to understand the diversity and collaboration among functional bacteria. Meanwhile, two TCEP-degrading strains affiliated with Xanthobacter and Ancylobacter were isolated. Xanthobacter sp. strain T2-1 was able to degrade both TCEP and BCEP following the pseudo-first-order kinetics with reaction rates of 1.66 h for TCEP and 1.02 h for BCEP, respectively. Ancylobacter sp. strain T3-4 could degrade TCEP following the pseudo-first-order kinetics with a reaction rate of 2.54 h, but is unable to degrade BCEP. Additionally, strains that were phylogenetically closely related were found to have different degradation capabilities toward TCEP and/or BCEP, indicating the importance to investigate functional genes such as phosphoesterase genes.
三（2-氯乙基）磷酸酯（TCEP）因其普遍存在的污染、毒性和持久性而受到全球越来越多的关注。在这项研究中，我们研究了以 TCEP 及其两种主要转化产物双（2-氯乙基）磷酸酯（BCEP）和 2-氯乙醇（2-CE）为唯一碳源的好氧富集培养物中的细菌群落。伯克霍尔德氏菌目和根瘤菌目可能是参与 TCEP 水解的两个主要细菌类群，而根瘤菌目和鞘脂单胞菌目可能在 BCEP 水解中发挥重要作用，因为当碳源从 TCEP 切换到 BCEP 时，根瘤菌目和鞘脂单胞菌目相关的磷酸酯酶基因增加。所有的伯克霍尔德氏菌目、根瘤菌目和鞘脂单胞菌目可能在 2-CE 代谢中效率很高，因为它们的脱氢酶基因和脱卤酶基因在 2-CE 富集后增加。不同细菌类群对不同底物的偏好强调了理解功能细菌多样性和协作的重要性。同时，分离到两株属于黄单胞菌属和Ancylobacter 的 TCEP 降解菌株。黄单胞菌属菌株 T2-1 能够以准一级动力学降解 TCEP 和 BCEP，其反应速率分别为 1.66 h 和 1.02 h。Ancylobacter sp. 菌株 T3-4 能够以准一级动力学降解 TCEP，反应速率为 2.54 h，但不能降解 BCEP。此外，发现系统发育上密切相关的菌株对 TCEP 和/或 BCEP 具有不同的降解能力，这表明需要研究磷酸酯酶等功能基因。
