Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China.
Environ Pollut. 2020 Oct;265(Pt B):114922. doi: 10.1016/j.envpol.2020.114922. Epub 2020 Jun 5.
Only limited information is available on bacterial communities' dynamics on tire microplastics in urban water environments. This study exploited 16S rDNA high-throughput sequencing to characterize bacterial communities on tire microplastics, using three different tire brands and tire sizes, in two typical urban water environments, including an influent pond of constructed wetland (CW) and its subsequent effluent into a landscape river (LR) during three different periods, namely, 1 month, 3 and 6 months. Results showed that the abundance of bacterial colonization on tire microplastics will increase over time. Proteobacteria, Bacteroidetes were the dominant bacteria at a phylum level, although they exhibited dynamic changes. At a genus level, the identifiable bacteria found in tire microplastics was generally the common bacteria in wastewater discharge, such as Aquabacterium and Denitratisoma. Additionally, alpha diversity showed no significant differences in bacterial communities at the same locations. While beta diversity showed that the bacterial communities on the tire microplastics in the two locations was different. BugBase revealed that tire microplastics could support pathogenic bacteria in urban water environments. PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) indicated that the abundance of microorganisms associated with metabolism and degradation increased with time. Moreover, the ambient environmental factors were the main influencing factors of bacterial communities on tire microplastics. Herein, the contribution rate of nutrient salts (NO-N, NO-N, NH-N, CODcr) was approximately 63%, and that of environmental physical factors of T and pH was 50%. While physicochemical factors, including particle size, contact angle, element content only had a slight impact. Accordingly, tire microplastics, as an emerging environmental pollutant, can act as carries for bacterial colonization and propagation, particularly harmful microorganisms. Therefore, the obtained findings can provide new insight into potential risks of harmful microorganisms that colonize tire microplastics in urban water environments.
关于轮胎微塑料在城市水环境中的细菌群落动态，目前仅有有限的信息。本研究利用 16S rDNA 高通量测序技术，采用三种不同品牌和尺寸的轮胎，在两个典型的城市水环境中，包括人工湿地进水池塘（CW）及其随后流入景观河（LR），对轮胎微塑料上的细菌群落进行了特征描述，在三个不同时期，即 1 个月、3 个月和 6 个月，进行了研究。结果表明，细菌在轮胎微塑料上的定殖丰度会随时间而增加。在门水平上，变形菌门和拟杆菌门是主要的细菌，尽管它们表现出动态变化。在属水平上，在轮胎微塑料上发现的可识别细菌通常是污水排放中的常见细菌，如 Aquabacterium 和 Denitratisoma。此外，同一地点的细菌群落的 alpha 多样性没有显著差异。而 beta 多样性表明，两个地点的轮胎微塑料上的细菌群落是不同的。BugBase 表明，轮胎微塑料可以在城市水环境中支持病原菌。PICRUSt（通过未观察到状态的重建来研究群落的系统发育）表明，与代谢和降解相关的微生物的丰度随时间增加。此外，环境因素是轮胎微塑料上细菌群落的主要影响因素。在此，营养盐（NO-N、NO-N、NH-N、CODcr）的贡献率约为 63%，环境物理因素 T 和 pH 的贡献率为 50%。而理化因素，包括粒径、接触角、元素含量，只有轻微的影响。因此，作为一种新兴的环境污染物，轮胎微塑料可以作为细菌定殖和繁殖的载体，特别是有害微生物。因此，研究结果可以为城市水环境中定殖轮胎微塑料的有害微生物的潜在风险提供新的认识。
