Microplastics are ubiquitous in marine ecosystems and are suitable matrices for bacterial attachment and growth. Studies on the microbes growing on plastics are mainly done using flow cytometry and massive sequencing, which do not allow for the quantification of specific groups and their activity. Here we present the results from a mesocosm experiment, designed to compare the effects of biodegradable and conventional microplastics on planktonic communities of the Baltic Sea. Our specific aim was to study the effects on bacterial activity and abundance using epifluorescence microscopy techniques. Specifically, we applied BONCAT-FISH which simultaneously allows for phylogenetic identification and the detection of the activity of individual bacterial cells. In our experiment, mesocosms were filled with Baltic brackish seawater and amended with 20 microplastic beads·ml-1 in triplicates for several treatments: (i) None (control), (ii) PS, (iii) PLGA and (iv) PS + PLGA. Our results show a low impact of the presence and quality of microplastics on marine bacterial communities during the first 11 days of exposure, with only weak differences in the activity of bacterial communities growing with biodegradable or conventional microplastics additions.

中文翻译：

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传统和可生物降解微塑料对海洋微生物群落的微弱影响


微塑料在海洋生态系统中无处不在，是细菌附着和生长的合适基质。对塑料上生长的微生物的研究主要使用流式细胞术和大规模测序来完成，这不允许量化特定群体及其活性。在这里，我们展示了中宇宙实验的结果，该实验旨在比较可生物降解和传统微塑料对波罗的海浮游生物群落的影响。我们的具体目标是使用落射荧光显微镜技术研究对细菌活性和丰度的影响。具体来说，我们应用了 BONCAT-FISH，它同时允许系统发育鉴定和检测单个细菌细胞的活性。在我们的实验中，中宇宙充满波罗的海咸淡水，并用 20 个微塑料珠·ml-1 一式三份进行修饰，进行多次处理：（i） 无（对照）、（ii） PS、（iii） PLGA 和 （iv） PS + PLGA。我们的结果表明，在暴露的前 11 天内，微塑料的存在和质量对海洋细菌群落的影响很小，添加可生物降解或常规微塑料后生长的细菌群落活性只有微弱的差异。