Guangdong Provincial Key Laboratory of Marine Biology, College of Science, Shantou University, Shantou, China; Department of Biology, College of Science, Shantou University, Shantou, China.
NHC Key Laboratory of Tropical Disease Control, School of Tropical Medicine, Hainan Medical University, Haikou, Hainan 571199, China.
J Hazard Mater. 2024 Dec 5;480:135759. doi: 10.1016/j.jhazmat.2024.135759. Epub 2024 Sep 11.
As a typical polycyclic aromatic hydrocarbon (PAH), phenanthrene is often present in diverse environments, leading to severe environmental contamination. However, bacterial degradation plays a crucial role in remediating phenanthrene contamination and has been widely adopted. The widely distributed marine Roseobacter-clade bacteria are frequently found in phenanthrene-contaminated environments, but their catalyzing ability and related molecular mechanism have been rarely elucidated. Our previous work showed Ruegeria sp. PrR005 isolated from the Pearl River Estuary sediment could degrade phenanthrene and other PAHs. Integrated approaches including multi-omics and biochemical analysis were applied here to explore its catabolism mechanism. The genomic and transcriptomic analysis indicated that six new P450 monooxygenase proteins could be closely associated with phenanthrene degradation. Heterologous expression of P450 monooxygenase candidates revealed that PrR005_00615, PrR005_04282, PrR005_04577 have considerable activity in phenanthrene removal, with PrR005_00615 being the primary contributor. Further, the biochemical and metabolic analysis revealed that PrR005_00615 could catalyze phenanthrene to phenanthrene-9,10-epoxide by introducing an oxygen atom at 9,10-carbon positions, which functioned as a monooxygenase. The present study provides compelling evidences of a novel enzyme responsible for catalyzing the initial step of phenanthrene transformation in PrR005. These findings hold significant importance in unraveling the mechanism behind phenanthrene degradation by Roseobacter-clade bacteria.
作为一种典型的多环芳烃（PAH），菲经常存在于各种环境中，导致严重的环境污染。然而，细菌降解在修复菲污染方面起着至关重要的作用，并得到了广泛应用。广泛分布的海洋玫瑰杆菌群细菌经常在菲污染的环境中被发现，但它们的催化能力及其相关的分子机制尚未得到充分阐明。我们之前的工作表明，从珠江口沉积物中分离出的 Ruegeria sp. PrR005 可以降解菲和其他多环芳烃。本研究采用多组学和生化分析相结合的方法，探讨其代谢机制。基因组和转录组分析表明，有六个新的 P450 单加氧酶蛋白可能与菲的降解密切相关。P450 单加氧酶候选基因的异源表达表明，PrR005_00615、PrR005_04282、PrR005_04577 在去除菲方面具有相当高的活性，其中 PrR005_00615 是主要贡献者。进一步的生化和代谢分析表明，PrR005_00615 可以通过在 9,10-碳位引入一个氧原子将菲催化为菲-9,10-环氧化物，从而发挥单加氧酶的作用。本研究提供了有力的证据，证明了 PrR005 中一种新型酶负责催化菲转化的初始步骤。这些发现对于揭示玫瑰杆菌群细菌降解菲的机制具有重要意义。
