解环菌中荧蒽降解途径的解析及其与海杆菌协同降解荧蒽的分子机制研究

荧蒽在环境中广泛存在，具有基因毒性，并且能够增强B[a]P的致癌性。微生物降解是荧蒽从环境中去除的主要途径。目前，对于荧蒽生物降解途径的认识主要来源于革兰氏阳性细菌中的分枝杆菌属（Mycobacterium）和红球菌属（Rhodococcus）的降解菌。本研究所涉及的从黄海沉积物分离到的3株不同的解环菌属细菌（Cycloclasticus spp.）是为数不多的能够降解荧蒽的革兰氏阴性海洋细菌，其荧蒽降解关键酶基因及降解途径均未见报道。前期研究还发现，尽管协同菌株（海杆菌）本身并不能降解荧蒽，但它与荧蒽降解菌（解环菌）在共培养条件下可以提高其对荧蒽的降解率，细菌间协同降解荧蒽等高分子量多环芳烃（HMW PAHs）的分子机制值得深入研究。本研究拟采用多重组学方法，期望从3株解环菌中发现荧蒽降解关键酶基因、提出革兰氏阴性细菌中的荧蒽降解途径、并阐释海杆菌协同解环菌降解荧蒽的分子机制。

Fluoranthene is ubiquitous in the environment, exhibits genotoxicity and can potentiate the carcinogenicity of benzo[a]pyrene. The removal of fluoranthene from contaminated environment is mainly through microbial biodegradation. At present, our knowledge about the fluoranthene-biodegradative pathway is mainly derived from the Gram-positive strains of the genus Mycobacterium and Rhodococcus. In this study, the three strains of the genus Cycloclasticus isolated from Yellow Sea sediments are representative Gram-negative fluoranthene degraders, the fluoranthene-degradative genes and pathway of which are still unknown. In our previous study, although Marinobacter sp. D15-8W could not degrade fluoranthene, it did enhance the degradation rates of fluoranthene by Cycloclasticus spp.. It is worthy to study the molecular mechanism underlying the synergic effect by bacterial consortium in high molecular weight PAHs biodegradation including fluoranthene. In this study, we aimed to elucidate the fluoranthene-degradative genes and pathway in Cycloclasticus spp. and the molecular mechanism of its synergic effect with Marinobacter spp. in fluoranthene biodegradation by a polyomic approach.