State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, People's Republic of China; Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing, 400045, China.
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, People's Republic of China; Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing, 400045, China.
Environ Pollut. 2022 Jul 15;305:119301. doi: 10.1016/j.envpol.2022.119301. Epub 2022 Apr 13.
The widely detected pyrene (PYR) is prone to accumulate and pose risks to the soil ecosystem. In this study, an aerobic closed microcosm was constructed to assess the effects of PYR at the environmental concentration (12.09 mg kg) on the structure, interactions, and metabolism of carbon sources of soil microbial communities. The results found that half-life of PYR was 37 d and its aerobic biodegradation was mainly implemented by both Gram-negative and Gram-positive bacteria as revealed by the quantitative results. High-throughput sequencing based on 16 S rRNA and ITS genes showed that PYR exposure interfered more significantly with the diversity and abundance of the bacterial community than that of the fungal community. For bacteria, rare species were sensitive to PYR, while Gemmatimonadota, Gaiellales, and Planococcaceae involved in organic pollutants detoxification and degradation were tolerant of PYR stress. Co-occurrence network analysis demonstrated that PYR enhanced the intraspecific cooperation within the bacterial community and altered the patterns of trophic interaction in the fungal community. Furthermore, the keystone taxa and their topological roles were altered, potentially inducing functionality changes. Function annotation suggested PYR inhibited the nitrogen fixation and ammonia oxidation processes but stimulated methylotrophy and methanol oxidation, especially on day 7. For the metabolism, microbial communities accelerated the metabolism of nitrogenous carbon sources (e.g. amine) to meet the physiological needs under PYR stress. This study clarifies the impacts of PYR on the structure, metabolism, and potential N and C cycling functions of soil microbial communities, deepening the knowledge of the environmental risks of PYR.
多环芳烃（PYR）广泛存在，易于在土壤中积累，对土壤生态系统构成威胁。本研究构建了好氧封闭微宇宙，以评估环境浓度（12.09mgkg）下 PYR 对土壤微生物群落碳源结构、相互作用和代谢的影响。结果发现，PYR 的半衰期为 37d，其好氧生物降解主要由革兰氏阴性菌和革兰氏阳性菌共同完成，这是通过定量结果揭示的。基于 16S rRNA 和 ITS 基因的高通量测序表明，PYR 暴露对细菌群落的多样性和丰度的干扰比对真菌群落的更为显著。对于细菌，稀有物种对 PYR 敏感，而 Gemmatimonadota、Gaiellales 和 Planococcaceae 参与有机污染物解毒和降解，对 PYR 胁迫具有耐受性。共现网络分析表明，PYR 增强了细菌群落内的种内合作，并改变了真菌群落中营养相互作用的模式。此外，关键分类群及其拓扑角色发生了改变，可能导致功能发生变化。功能注释表明，PYR 抑制了固氮和氨氧化过程，但刺激了甲基营养和甲醇氧化，尤其是在第 7 天。对于代谢，微生物群落加速了含氮碳源（如胺）的代谢，以满足 PYR 胁迫下的生理需求。本研究阐明了 PYR 对土壤微生物群落结构、代谢和潜在氮、碳循环功能的影响，深化了对 PYR 环境风险的认识。
