Bonn Institute for Organismic Biology, Section 2, Animal Diversity, University of Bonn, Bonn, Germany.
Institute of Zoology, University of Cologne, Cologne, Germany.
Environ Microbiol Rep. 2024 Oct;16(5):e70016. doi: 10.1111/1758-2229.70016.
Microplastics (MPs) are released into the environment through human activities and are transported by rivers from land to sea. Biofilms, which are ubiquitous in aquatic ecosystems such as rivers, may play an essential role in the fate of MPs and their ingestion by biofilm protists. To assess this, biofilms were naturally grown on clay tiles in the River Rhine, Germany, and analysed in a combined field and laboratory study. Compared to the ambient river water, biofilms grown for 6, 12, and 18 months in the River Rhine contained up to 10 times more MPs. Between 70% and 78% of all MPs were smaller than 50 μm. In laboratory experiments, clay tiles covered with 1-month-old naturally grown biofilm retained 6-12 times more MPs than clay tiles without biofilm coverage. Furthermore, the ingestion of MPs of 6 and 10 μm by the ciliate Stentor coeruleus was confirmed, and a positive correlation between ingestion rates and ambient MP concentrations was found. The results are relevant for particle transport models in riverine systems, risk assessment of MPs regarding their distribution and fate in the aquatic environment, and the effects of MPs on micro- and macroorganisms.
微塑料（MPs）通过人类活动释放到环境中，并通过河流从陆地输送到海洋。生物膜在河流等水生生态系统中无处不在，它们可能在 MPs 的命运及其被生物膜原生动物摄取方面发挥重要作用。为了评估这一点，在德国莱茵河中自然生长的粘土瓦片上进行了自然生长的生物膜的现场和实验室联合研究。与环境河水中相比，在莱茵河中生长 6、12 和 18 个月的生物膜中含有多达 10 倍的 MPs。所有 MPs 中，有 70%到 78%的 MPs 小于 50μm。在实验室实验中，覆盖有 1 个月大的自然生长生物膜的粘土瓦片比没有生物膜覆盖的粘土瓦片保留的 MPs 多 6-12 倍。此外，还证实了纤毛虫 Stentor coeruleus 摄取了 6 和 10μm 的 MPs，并且发现摄取率与环境 MP 浓度之间存在正相关。研究结果与河流系统中的颗粒传输模型、 MPs 在水生环境中的分布和命运的风险评估以及 MPs 对微生物和宏观生物的影响有关。
