Water Research Institute, CNR-IRSA, National Research Council, Rome, Italy.
Water Research Institute, CNR-IRSA, National Research Council, Rome, Italy.
Water Res. 2020 Dec 15;187:116429. doi: 10.1016/j.watres.2020.116429. Epub 2020 Sep 15.
In this study, 16S rRNA gene high throughput sequencing and Fluorescence In Situ Hybridization (FISH) combined with confocal laser scanning microscopy (CLSM) were used to assess for the first time biodiversity and structure of microplastic-associated biofilms (plastisphere) collected from Italian lentic ecosystems. The analysis revealed clear differences in microbial community composition among biofilms and corresponding planktonic populations indicating a selective adhesion on microplastics (MP). Although geographical variations in taxa composition were observed, a plastisphere core microbiome, composed by known biofilm formers found in freshwater ecosystems (e.g. Sphingorhabdus, Sphingomonas, Rhodobacter, Aquabacterium and Acidovorax genera) was found. Species composition of plastisphere did not substantially differ between the diverse polymers, while a clear link with the MP exposure time was found by Fourier Transform Infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) analysis. Generalist planktonic taxa (e.g. members of the families Sphingomonadaceae and Rhodobacteraceae) were found on MPs with the lowest degradation level whereas the biodiversity increased with the increase of MP degradation. FISH-CLSM analysis confirmed the Burkolderiaceae dominance in most of the analyzed plastisphere samples and revealed a patchy microbial colonization and a complex biofilm architecture with bacterial micro-colonies and cyanobacterial aggregates occurring together with microalgae assemblages.
在这项研究中，我们首次使用 16S rRNA 基因高通量测序和荧光原位杂交（FISH）结合共聚焦激光扫描显微镜（CLSM），评估了从意大利内陆生态系统中收集的微塑料相关生物膜（塑料圈）的生物多样性和结构。分析结果显示，生物膜和相应浮游种群的微生物群落组成存在明显差异，表明微生物对微塑料具有选择性附着。尽管观察到了分类群组成的地理差异，但仍发现了一个由已知的淡水生态系统中的生物膜形成菌（如鞘氨醇单胞菌属、单胞菌属、红杆菌属、噬水气单胞菌属和食酸菌属）组成的塑料圈核心微生物组。塑料圈的物种组成在不同聚合物之间没有显著差异，而傅里叶变换红外光谱（FT-IR）和扫描电子显微镜（SEM）分析发现，塑料圈的物种组成与 MP 的暴露时间有明显的联系。在降解水平最低的 MPs 上发现了具有普遍性的浮游生物分类群（例如鞘氨醇单胞菌科和红杆菌科的成员），而随着 MP 降解程度的增加，生物多样性也随之增加。FISH-CLSM 分析证实了伯克霍尔德氏菌科在大多数分析的塑料圈样本中的优势地位，并揭示了微生物的斑块状定殖和复杂的生物膜结构，其中存在细菌微群落和与微藻组合在一起的蓝细菌聚集体。
