ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) are key organic pollutants in the environment that pose threats to the ecosystem and human health. The degradation of high molecular weight (HMW) PAHs by enriched bacterial consortia has been previously studied, while the involved metabolisms and microbial communities are still unclear and warrant further investigations. In this study, five bacterial consortia capable of utilizing different PAHs (naphthalene, anthracene, and pyrene) as the sole carbon and energy sources were enriched from PAH-contaminated soil samples. Among the five consortia, consortium TC exhibited the highest pyrene degradation efficiency (91%) after 19 d of incubation. The degradation efficiency was further enhanced up to 99% by supplementing yeast extract. Besides, consortium TC showed tolerances to high concentrations of pyrene (up to 1000 mg/L) and different heavy metal stresses (including Zn²⁺, Cd²⁺, and Pb²⁺). The dominant genus in consortium TC, GS, and PL showing relatively higher degradation efficiency for anthracene and pyrene was Pseudomonas, whereas consortium PG and GD were predominated by genus Achromobacter and class Enterobacteriaceae, respectively. Consortium TC, as a highly efficient HMW PAH-degrading consortium, could be applied for synergistic biodegradation of HMW PAHs and in situ bioremediation of the sites contaminated with both PAHs and heavy metals.

摘要

多环芳烃（PAHs）是环境中的主要有机污染物，对生态系统和人类健康构成威胁。先前已经研究了富集细菌聚生体对高分子量（HMW）PAHs的降解，而所涉及的代谢和微生物群落仍不清楚，需要进一步研究。在这项研究中，从多环芳烃污染的土壤样品中富集了五种能够利用不同多环芳烃（萘、蒽和芘）作为唯一碳源和能源的细菌聚生体。在五个联合体中，联合体 TC 在孵化 19 天后表现出最高的芘降解效率 (91%)。通过补充酵母提取物，降解效率进一步提高至 99%。除了，²⁺、 Cd ²⁺和 Pb ²⁺ )。对蒽和芘的降解效率相对较高的 TC、GS 和 PL 菌群中的优势属是假单胞菌属，而 PG 和 GD 菌群分别以无色杆菌属和肠杆菌科为主。Consortium TC作为一种高效降解HMW PAHs的联合体，可用于HMW PAHs的协同生物降解和多环芳烃和重金属污染场地的原位生物修复。