Miami College, Henan University, Kaifeng, 475000, Henan, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.
Environ Pollut. 2022 Sep 1;308:119730. doi: 10.1016/j.envpol.2022.119730. Epub 2022 Jul 6.
PAHs have been widely detected to accumulate in saline and hypersaline environments. Moderately halophilic microbes are considered the most suitable player for the elimination of PAHs in such environments. In this study, consortium 5H was enriched under 5% salinity and completely degraded phenanthrene in 5 days. By high-throughput sequencing, consortium 5H was identified as being mainly composed of Methylophaga, Marinobacter and Thalassospira. Combined with the investigation of intermediates and enzymatic activities, the degradation pathway of consortium 5H on phenanthrene was proposed. Consortium 5H was identified as having the ability to tolerate a wide range of salinities (1%-10%) and initial PAH concentrations (50 mg/L to 400 mg/L). It was also able to function under neutral to weak alkaline conditions (pH from 6 to 9) and the phytotoxicity of the produced intermediates showed no significant difference with distilled water. Furthermore, the metagenome of consortium 5H was measured and analyzed, which showed a great abundance of catabolic genes contained in consortium 5H. This study expanded the knowledge of PAH-degradation under hypersaline environments and consortium 5H was proposed to have good potential for the elimination of PAH pollution in saline/hypersaline environments.
多环芳烃（PAHs）已被广泛发现会在盐沼和高盐环境中积累。中度嗜盐微生物被认为是在这些环境中消除 PAHs 的最合适的参与者。在本研究中，在 5%盐度下富集了 5H 共生物，并在 5 天内完全降解了菲。通过高通量测序，共生物 5H 被鉴定主要由甲基球菌属（Methylophaga）、海洋杆菌属（Marinobacter）和海洋螺旋菌属（Thalassospira）组成。结合中间产物和酶活性的研究，提出了 5H 共生物降解菲的途径。共生物 5H 被鉴定为具有耐受广泛盐度（1%-10%）和初始 PAH 浓度（50mg/L 至 400mg/L）的能力。它还能够在中性至弱碱性条件（pH 值为 6 至 9）下发挥作用，且产生的中间产物的植物毒性与蒸馏水相比没有显著差异。此外，还测量和分析了共生物 5H 的宏基因组，结果表明共生物 5H 中含有大量的降解基因。本研究扩展了在高盐环境中 PAH 降解的知识，共生物 5H 被提议具有在盐沼/高盐环境中消除 PAH 污染的良好潜力。
