Xu Chenye, Hu Chun, Lu Jiawei, Yang Tong, Shen Chensi, Li Fang, Wang Jie
College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
J Hazard Mater. 2024 Jan 5;461:132693. doi: 10.1016/j.jhazmat.2023.132693. Epub 2023 Oct 2.
The not-homogenous microplastics (MPs) distribution in freshwaters results in distinct microbial communities. Yet knowledge regarding plastisphere in metabolic pathways and element cycling behaviors remains limited. In this study, we collected MPs from 15 sampling sites in the Taihu Lake in China, and found that MPs were widely distributed in this freshwater lake, and dominantly composed of fibrous polyethylene terephthalate. Based on the metagenomic analysis, we found that MPs were colonized by Bacteroidia, Alpha-Proteobacteria, and Bacilli as a filter, but depleted in Verrucomicrobiae. Potential pathogens of plant eudicots and monocots were significantly enriched in plastisphere. Predicted functional profiles involved in the metabolism of other amino acids, biosynthesis of other secondary metabolites, and glycan biosynthesis and metabolism were overrepresented in plastisphere. Regarding elemental cycling, functional genes related to nitrogen fixation and nitrification showed 39.6% and 67.5% decline in plastisphere, whereas the genes involved in denitrification and nitrate reduction were significantly enriched. For sulfur cycles, the plastisphere exhibited higher sulfate reduction and sulfur oxidation system activities. Additionally, the taxonomic compositions and predicted functions in the plastispheres were mainly driven by the stochastic processes, while the deterministic processes were more important for the planktonic communities. The distinctions in the microbial composition, the predicted functionality, and the underly mechanisms between plastisphere and planktonic communities illustrated the unique ecology of the new anthropogenic-related plastisphere ecosystems.
淡水环境中微塑料（MPs）分布不均导致微生物群落各异。然而，关于塑料球在代谢途径和元素循环行为方面的知识仍然有限。在本研究中，我们从中国太湖的15个采样点收集了微塑料，发现微塑料在这个淡水湖中广泛分布，且主要由纤维状聚对苯二甲酸乙二酯组成。基于宏基因组分析，我们发现拟杆菌纲、α-变形菌纲和芽孢杆菌属作为过滤器在微塑料上定殖，但疣微菌门数量减少。双子叶植物和单子叶植物的潜在病原体在塑料球中显著富集。预测涉及其他氨基酸代谢、其他次生代谢物生物合成以及聚糖生物合成和代谢的功能谱在塑料球中过度富集。关于元素循环，与固氮和硝化作用相关的功能基因在塑料球中分别下降了39.6%和67.5%，而参与反硝化作用和硝酸盐还原的基因则显著富集。对于硫循环，塑料球表现出更高的硫酸盐还原和硫氧化系统活性。此外，塑料球中的分类组成和预测功能主要由随机过程驱动，而确定性过程对浮游生物群落更为重要。塑料球和浮游生物群落之间微生物组成、预测功能及潜在机制的差异说明了新的人为相关塑料球生态系统的独特生态学特征。
