Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, People's Republic of China, 210098; School of Environment, Nanjing Normal University, Nanjing, 210023, People's Republic of China.
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, People's Republic of China, 210098.
Environ Pollut. 2023 Mar 1;320:121092. doi: 10.1016/j.envpol.2023.121092. Epub 2023 Jan 16.
Microplastics (MPs) are emerging contaminants in aquatic environments, yet their impact on sediment microbiota and biogeochemical processes were not well reported. Herein, microcosm experiments were performed to investigate the effects of MPs (Polystyrene, PS and Polyethylene, PE) with three size classes (ranging from 100 nm to 150-200 μm) on sediment bacterial and fungal communities over 60-day incubation from Taihu Lake. High-throughput sequencing revealed the alpha diversities of bacterial and fungal communities were reduced by MPs, dependent on MPs' size and type. Bacterial community structures were significantly altered under all MPs treatments, with clustering for the same size class for PS and PE. Fungal community structures were significantly affected for all MPs, with PS and PE exhibiting different effects. Co-occurrence network analysis suggested MPs changed bacterial and fungal network complexities. Proteobacteria and Ascomycota formed strong associations with other phyla and demonstrated tolerance to MPs exposure. Actinobacteria, Firmicutes, and Chytridiomycota were the main respondents to MPs. The enzyme concentrations were stimulated by MPs, indicating carbon and nitrogen uptakes might be increased. Therefore, PS and PE had similar impacts on the microbial community (particularly bacteria), and sizes of MPs were the main influencing factors. MPs shifted community structure and network with distinct responses from bacteria and fungi, likely leading to the alteration of microbial-involved carbon and nitrogen cycling.
微塑料（MPs）是水生环境中的新兴污染物，但它们对沉积物微生物群和生物地球化学过程的影响尚未得到充分报道。本研究通过微宇宙实验，研究了三种尺寸范围（100nm 至 150-200μm）的 MPs（聚苯乙烯、PS 和聚乙烯、PE）对太湖沉积物细菌和真菌群落的影响，实验为期 60 天。高通量测序结果表明，MPs 降低了细菌和真菌群落的α多样性，这取决于 MPs 的尺寸和类型。在所有 MPs 处理下，细菌群落结构均发生了显著变化，PS 和 PE 呈现出相同尺寸的聚类。所有 MPs 均显著影响真菌群落结构，PS 和 PE 表现出不同的影响。共生网络分析表明 MPs 改变了细菌和真菌网络的复杂性。变形菌门和子囊菌门与其他门形成了强烈的关联，表现出对 MPs 暴露的耐受性。放线菌门、厚壁菌门和壶菌门是对 MPs 主要响应的菌门。MPs 刺激了酶浓度的升高，表明碳氮的吸收可能增加。因此，PS 和 PE 对微生物群落（特别是细菌）有相似的影响，而 MPs 的尺寸是主要影响因素。MPs 改变了群落结构和网络，细菌和真菌的响应存在差异，可能导致微生物参与的碳氮循环的改变。
