Pyrene biodegradation and its potential pathway involving Roseobacter clade bacteria
Pyrene biodegradation and its potential pathway involving Roseobacter clade bacteria
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DOI：
10.1016/j.ibiod.2020.104961
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发表时间：
2020-05
影响因子：
4.8
通讯作者：
Haixin Zhou;Shuangfei Zhang;Jinli Xie;Huan Wei;Zhong Hu;Hui Wang
中科院分区：
文献类型：
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作者：
Haixin Zhou;Shuangfei Zhang;Jinli Xie;Huan Wei;Zhong Hu;Hui Wang
微生物矿化作用在去除污染环境中的多环芳烃(PAHs)方面具有重要作用。隶属于玫瑰杆菌支系的细菌在各种环境中普遍存在并大量存在，包括多环芳烃污染地区。然而，对玫瑰杆菌分支利用的多环芳烃降解机制知之甚少。本研究从珠江口沉积物中分离到8株细菌，分属于玫瑰杆菌支系。研究了分离的8株玫瑰杆菌分支细菌(RCB)和3株其他类型菌株对芘和另外两种典型的多环芳烃(菲和苯并[a]芘)的降解作用。结果表明，以多环芳烃为唯一碳源时，所有菌株对多环芳烃的降解率均较低。然而，在补充替代碳源后，降解被极大地刺激。这意味着RCB通过共代谢途径降解多环芳烃。在基因组分析的基础上，重新构建了RCB中可能存在的Py降解途径，并在RCB基因组中检测到了一个多环芳烃降解的功能标记基因pahE。在测试菌株中还鉴定出PAH环羟化双加氧酶α亚单位结构域家族和β亚单位结构域家族，以及与PAH降解相关的Rieske[2FE-2S]结构域。这些发现为RCB能够通过多种代谢途径降解多环芳烃提供了基本证据。
Microbial mineralization plays a significant role in the removal of polycyclic aromatic hydrocarbons (PAHs) from polluted environments. Bacteria affiliated to the Roseobacter clade are ubiquitous and abundant in various environments, including PAH-polluted areas. However, very little is known about the PAH degradation mechanism utilized by the Roseobacter clade. In this study, eight bacterial strains belonging to the Roseobacter clade were isolated from sediments collected from the estuary of the Pearl River. Degradation of pyrene and two other typical PAHs (phenanthrene and benzo[a]pyrene) was studied in the eight isolated strains of Roseobacter clade bacteria (RCB) and three other type strains. The results revealed that all strains had low PAH-degrading efficiency when PAHs were used as the sole source of carbon. However, upon supplementation with an alternative carbon source, the degradation was greatly stimulated. This implies that RCB degrade PAHs via a co-metabolism pathway. A putative pyrene degradation pathway in RCB was re-constructed based on genomic analysis.pahE, a functional marker gene for PAH degradation, was detected in the genomes of RCB. PAH ring-hydroxylating dioxygenase alpha subunit domain family and beta subunit domain family and PAH degradation-related Rieske [2Fe–2S] domain were also identified in the test strains. These findings provide fundamental evidence that RCB are capable of degrading PAHs through a versatile metabolic pathway.