Du Jingjing, Wang Xilin, Tao Tianying, Zhang Xueting, Jin Baodan, Zhao Jianguo, Lv Yangyang, Zhang Qian, Hu Keying, Qv Wenrui, Xu Yuanqian, Cao Xia
School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, China; Key Laboratory of Pollution Treatment and Resource, China National Light Industry, Zhengzhou, China.
School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
Sci Total Environ. 2023 Dec 20;905:167032. doi: 10.1016/j.scitotenv.2023.167032. Epub 2023 Sep 12.
The particle size of plastic is one of the most important factors influencing its ecotoxicity, but we are unclear about the effect of polystyrene (PS) particle size on microbial decomposers and consequent nutrient cycling in streams. Here, using microcosm experiments, we assessed how three PS sizes (50 nm, 1 μm, and 20 μm) influenced the process and consequences of leaf litter decomposition. Under acute exposure to 1 μm and 20 μm PS, fungal biomass significantly decreased, but microbial biomass significantly increased, indicating compensations may work between fungi and other microbial decomposers. After chronic exposure to 50 nm and 1 μm PS, the leaf decomposition rate decreased by 19.27 % and 15.22 %, respectively, due to the reduced microbial enzyme activity, fungal diversity, and dominance of Anguillospora. As a result, the regeneration of nutrients, especially phosphorus, was significantly depressed, which might influence the primary productivity of streams. Therefore, our results suggest that nanoscale PS has a greater impact on microbial activity, thus affecting their functioning in leaf litter decomposition and consequent nutrient cycling. The findings provide a data support for the risk assessment of plastic pollution in freshwater systems.
塑料的粒径是影响其生态毒性的最重要因素之一，但我们尚不清楚聚苯乙烯（PS）粒径对溪流中微生物分解者以及随之而来的养分循环的影响。在此，我们通过微观实验评估了三种PS粒径（50纳米、1微米和20微米）如何影响落叶分解的过程及结果。在急性暴露于1微米和20微米的PS时，真菌生物量显著下降，但微生物生物量显著增加，这表明真菌与其他微生物分解者之间可能存在补偿作用。在长期暴露于50纳米和1微米的PS后，由于微生物酶活性降低、真菌多样性减少以及鳗孢菌的优势地位，落叶分解率分别下降了19.27%和15.22%。结果，养分尤其是磷的再生显著受到抑制，这可能会影响溪流的初级生产力。因此，我们的结果表明，纳米级PS对微生物活性有更大影响，从而影响它们在落叶分解及随之而来的养分循环中的功能。这些发现为淡水系统中塑料污染的风险评估提供了数据支持。
