Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
Sci Total Environ. 2019 Feb 10;650(Pt 2):2395-2402. doi: 10.1016/j.scitotenv.2018.09.378. Epub 2018 Oct 1.
Microplastics are frequently detected in freshwater environments, serving as a new factitious substrate for colonization of biofilm-forming microorganisms. Distinct microbial assemblages between microplastics and surrounding waters have been well documented; however, there is insufficient knowledge regarding biofilm colonization of plastic and non-plastic substrates, despite the fact that microbial communities generally aggregate on natural solid surfaces. In this study, the effects of substrate type on microbial communities were evaluated by incubation of biofilms on microplastic substrates (polyethylene and polypropylene) and natural substrates (cobblestone and wood) for 21 days under controlled conditions. Results from high-throughput sequencing of 16S rRNA revealed that the alpha diversity (richness, evenness, and diversity) was lower in the microplastic-associated communities than in those on the natural substrates, indicating substrate-type-coupled species sorting. Distinct community structure and biofilm composition were observed between these two substrate types. Significantly higher abundances of Pirellulaceae, Phycisphaerales, Cyclobacteriaceae, and Roseococcus were observed on the microplastic substrates compared with the natural substrates. Simultaneously, the functional profiles (KEGG) predicted by Tax4Fun showed that the pathways of amino acid metabolism and metabolism of cofactors and vitamins were increased in biofilms on the microplastic substrates. The findings illustrate that microplastic acts as a distinct microbial habitat (compared with natural substrates) that could not only change the community structure but also affect microbial functions, potentially impacting the ecological functions of microbial communities in aquatic ecosystems.
微塑料经常在淡水环境中被检测到，成为生物膜形成微生物定殖的新人工基质。微塑料和周围水体之间的微生物群落已经有了很好的记录；然而，对于塑料和非塑料基质的生物膜定殖，我们的了解还不够充分，尽管微生物群落通常会聚集在天然固体表面上。在这项研究中，通过在受控条件下将生物膜孵育在微塑料基质（聚乙烯和聚丙烯）和天然基质（鹅卵石和木材）上 21 天，评估了基质类型对微生物群落的影响。16S rRNA 的高通量测序结果表明，与天然基质上的群落相比，微塑料相关群落的 alpha 多样性（丰富度、均匀度和多样性）较低，表明基质类型与物种分选有关。这两种基质类型之间观察到明显不同的群落结构和生物膜组成。与天然基质相比，微塑料基质上的 Pirellulaceae、Phycisphaerales、Cyclobacteriaceae 和 Roseococcus 的丰度明显更高。同时，Tax4Fun 预测的功能谱（KEGG）表明，微塑料基质上生物膜中的氨基酸代谢和辅因子和维生素代谢途径增加。这些发现表明，微塑料作为一种独特的微生物栖息地（与天然基质相比），不仅可以改变群落结构，还可以影响微生物功能，可能会影响水生生态系统中微生物群落的生态功能。
