Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu, 210098, PR China; State Key Lab Hydraul & Mt River Engn, Sichuan University, Chengdu, Sichuan, 610065, PR China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu, 210098, PR China.
Environ Res. 2021 May;196:110371. doi: 10.1016/j.envres.2020.110371. Epub 2020 Oct 31.
Once in aquatic ecosystems, plastics can be easily colonized by diverse microbes, and these microbial communities on plastics-the 'plastisphere'-often differ from the communities in the surrounding water and other substrates. However, our knowledge of plastic-associated bacterial and fungal communities on diverse plastics in freshwater is poor, especially for fungal communities. Furthermore, intraspecies interactions among bacterial and fungal communities colonized on diverse plastics are poorly known. Here, we characterized the taxonomic composition and diversity of bacteria and fungi on three types of plastics in a lab-scale incubator with freshwater from an urban river. High-throughput sequencing revealed that the alpha diversity of bacterial communities was higher on polyethylene microplastics (MPs) than on polyethylene (PE) and polypropylene (PP) sheets. The structure of bacterial communities on MPs differed from those on plastic sheets. In contrast, no striking differences in alpha diversity and taxonomic composition were observed for fungal communities on different types of plastics. Members of Ascomycota, Basidiomycota, Blastocladiomycota and Mucoromycota dominated fungal assemblages on plastics. Co-occurrence network analysis revealed that the biotic interactions between bacteria and fungi on MPs were less complex than those on PE and PP sheets. The three types of plastics shared no keystone taxa. The functional profiles (KEGG) predicted by Tax4Fun showed that the pathways of alanine, aspartate, glutamate and biotin metabolism were enriched in biofilms on MPs. Nonetheless, the higher complexity of plastic sheet-associated biofilms might make them more resistant to environmental perturbation and facilitate the maintenance of microbial activities.
一旦进入水生生态系统，塑料很容易被各种微生物定殖，这些在塑料上的微生物群落——“塑料体”——通常与周围水和其他基质中的群落不同。然而，我们对淡水环境中不同塑料上与塑料相关的细菌和真菌群落的了解甚少，尤其是真菌群落。此外，在不同塑料上定殖的细菌和真菌群落之间的种内相互作用也知之甚少。在这里，我们在一个带有城市河流淡水的实验室规模培养箱中，研究了三种类型塑料上的细菌和真菌的分类组成和多样性。高通量测序结果表明，在聚乙烯微塑料（MPs）上的细菌群落的α多样性高于聚乙烯（PE）和聚丙烯（PP）片材上的细菌群落。MPs 上的细菌群落结构与塑料片上的不同。相比之下，在不同类型的塑料上，真菌群落的α多样性和分类组成没有明显差异。子囊菌门、担子菌门、芽枝孢菌门和毛霉门是真菌群落的主要组成部分。共生网络分析表明，MPs 上细菌和真菌之间的生物相互作用比在 PE 和 PP 片材上的要简单。这三种类型的塑料没有共享的关键类群。Tax4Fun 预测的功能谱（KEGG）表明，在 MPs 生物膜中，丙氨酸、天冬氨酸、谷氨酸和生物素代谢途径被富集。尽管如此，塑料片材相关生物膜的更高复杂性可能使它们更能抵抗环境扰动，并有助于维持微生物的活性。
