School of Environmental and Material Engineering, Yantai University, Yantai 264005, China.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Environ Sci Technol. 2022 Sep 6;56(17):12257-12266. doi: 10.1021/acs.est.2c02757. Epub 2022 Aug 12.
Massive microplastics are deposited in the coastal zone. Tire particles (TPs) are an important microplastic source, but little is known about how TPs affect the microbial community composition and function in coastal sediments and the role leachable additives play in TP toxicity. Here, a microcosm experiment was performed using coastal sediments amended with different doses of TPs and with their leachable additives to investigate their effects on the sediment microbial community composition and function. Environmentally relevant concentrations of TPs can change the microbial community structure, decrease community diversity, and inhibit nutrient cycling processes, including carbon fixation and degradation, nitrification, denitrification, and sulfur cycling in sediments. Notably, the raw TP and leachate treatments showed consistent effects. A variety of additives were found in the pore water of sediment, and they could explain over 90% of the variations of the community structure. Further modeling revealed that leachable additives not only directly influenced community function but also indirectly affected community diversity and function by shifting the community structure. In addition, rare taxa could be crucial mediators of ecological functions of sediment microbial community. Combined, this study provides novel insights into the role of TPs' leachable additives in affecting sediment microbial community and function.
大量的微塑料沉积在沿海地区。轮胎颗粒（TPs）是微塑料的一个重要来源，但人们对 TPs 如何影响沿海沉积物中的微生物群落组成和功能以及可浸出添加剂在 TPs 毒性中的作用知之甚少。在这里，使用添加了不同剂量 TPs 及其可浸出添加剂的沿海沉积物进行了微宇宙实验，以研究它们对沉积物微生物群落组成和功能的影响。与环境相关的 TPs 浓度会改变微生物群落结构，降低群落多样性，并抑制包括碳固定和降解、硝化、反硝化和硫循环在内的营养循环过程。值得注意的是，原始 TP 和浸出液处理表现出一致的效果。在沉积物的孔隙水中发现了多种添加剂，它们可以解释群落结构变化的 90%以上。进一步的模型表明，可浸出添加剂不仅直接影响群落功能，而且通过改变群落结构间接影响群落多样性和功能。此外，稀有分类群可能是沉积物微生物群落生态功能的关键调节因子。综上所述，本研究提供了关于 TPs 可浸出添加剂影响沉积物微生物群落和功能的新见解。
