Kettner Marie Therese, Oberbeckmann Sonja, Labrenz Matthias, Grossart Hans-Peter
Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.
Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany.
Front Microbiol. 2019 Mar 20;10:538. doi: 10.3389/fmicb.2019.00538. eCollection 2019.
Microplastics (MP) constitute a widespread contaminant all over the globe. Rivers and wastewater treatment plants (WWTP) transport annually several million tons of MP into freshwaters, estuaries and oceans, where they provide increasing artificial surfaces for microbial colonization. As knowledge on MP-attached communities is insufficient for brackish ecosystems, we conducted exposure experiments in the coastal Baltic Sea, an in-flowing river and a WWTP within the drainage basin. While reporting on prokaryotic and fungal communities from the same set-up previously, we focus here on the entire eukaryotic communities. Using high-throughput 18S rRNA gene sequencing, we analyzed the eukaryotes colonizing on two types of MP, polyethylene and polystyrene, and compared them to the ones in the surrounding water and on a natural surface (wood). More than 500 different taxa across almost all kingdoms of the eukaryotic tree of life were identified on MP, dominated by Alveolata, Metazoa, and Chloroplastida. The eukaryotic community composition on MP was significantly distinct from wood and the surrounding water, with overall lower diversity and the potentially harmful dinoflagellate being enriched on MP. Co-occurrence networks, which include prokaryotic and eukaryotic taxa, hint at possibilities for dynamic microbial interactions on MP. This first report on total eukaryotic communities on MP in brackish environments highlights the complexity of MP-associated biofilms, potentially leading to altered microbial activities and hence changes in ecosystem functions.
微塑料（MP）是全球范围内广泛存在的污染物。河流和污水处理厂每年将数百万吨微塑料输送到淡水、河口和海洋中，在这些地方，微塑料为微生物定殖提供了越来越多的人工表面。由于对咸淡水生态系统中附着在微塑料上的群落了解不足，我们在波罗的海沿岸、一条流入的河流以及流域内的一座污水处理厂进行了暴露实验。此前我们已报道过同一实验装置中的原核生物和真菌群落，在此我们将重点关注整个真核生物群落。通过高通量18S rRNA基因测序，我们分析了在两种类型的微塑料（聚乙烯和聚苯乙烯）上定殖的真核生物，并将它们与周围水体以及天然表面（木材）上的真核生物进行了比较。在微塑料上鉴定出了超过500种几乎涵盖真核生物生命之树所有界的不同分类单元，其中以囊泡虫类、后生动物和绿藻纲为主。微塑料上的真核生物群落组成与木材和周围水体显著不同，总体多样性较低，并且潜在有害的甲藻在微塑料上富集。包括原核生物和真核生物分类单元的共现网络暗示了微塑料上动态微生物相互作用的可能性。这份关于咸淡水环境中微塑料上整个真核生物群落的首次报告突出了与微塑料相关生物膜的复杂性，这可能会导致微生物活动改变，进而引起生态系统功能变化。
