School of Chemistry and Environment, Guangdong Ocean University, Zhanjiang, 524088, China; Shenzhen Institute of Guangdong Ocean University, Shenzhen, 518108, China.
School of Chemistry and Environment, Guangdong Ocean University, Zhanjiang, 524088, China.
Chemosphere. 2020 Aug;252:126565. doi: 10.1016/j.chemosphere.2020.126565. Epub 2020 Mar 19.
In recent years, global climate change and pollution of the marine environment have caused large-scale coral deaths and severe damages to coral reef ecosystems. Numerous studies have shown that coral diseases are closely related to microorganisms. And microplastics (MPs) are a potential threat to corals. In marine ecosystems, MPs are an emerging contaminant. MPs have a strong adsorption effect on pollutants in the water environment, and they are very easily colonized by microorganisms to form biofilms. Biofilms may accumulate many pathogens, increasing the probability of coral disease. However, there is no report about the composition of biofilms on the surface of microplastics in coral growth areas. In this study, nine kinds of MPs were chosen in the experiments, which are commonly found in the ocean. Four stakeout points were selected in the coral area. Biofilms were cultivated in natural environment. The composition and distribution of biofilms on the surface of the MPs were analyzed by 16 S rRNA sequencing. The characteristics of biofilms were observed by scanning electron microscopy (SEM). The experimental results show that the species composition and abundance distribution of the biofilm on the MP surface are significantly different from the surrounding seawater. The type of MPs and the stake out point are important factors affecting the structure of the biofilm bacterial community. Compared to seawater samples, MPs are enriched with certain dominant bacteria such as Vibrionaceae, Rhodobacteraceae, Flavobacteraceae, Microtrichaceae and Sphingomonadaceae. Among them, Vibrionaceae, Rhodobacteraceae and Flavobacteraceae are closely related to the tissue damage of stony corals, and Vibrios are also the main pathogens of coral albinism. In addition, Pseudomonas and Bbellvibrio cholerae are also detected on the MPs biofilm. SEM graphs of the MPs after culture could clearly observe rod-shaped bacteria and Streptococci. This study can provide a new direction for the study of coral toxicology by MPs and provide basic data for the toxicology research of MPs.
近年来，全球气候变化和海洋环境污染导致大规模珊瑚死亡，珊瑚礁生态系统遭受严重破坏。大量研究表明，珊瑚疾病与微生物密切相关。而微塑料（MPs）是珊瑚的潜在威胁。在海洋生态系统中，MPs 是一种新兴污染物。MPs 对水环境中的污染物具有很强的吸附作用，很容易被微生物定植形成生物膜。生物膜可能会积累许多病原体，增加珊瑚疾病的概率。然而，目前还没有关于珊瑚生长区微塑料表面生物膜组成的报道。在这项研究中，选择了实验中常见的九种 MPs，在珊瑚区选择了四个站位，在自然环境中培养生物膜。通过 16S rRNA 测序分析 MPs 表面生物膜的组成和分布，通过扫描电子显微镜（SEM）观察生物膜的特征。实验结果表明，MP 表面生物膜的物种组成和丰度分布与周围海水有显著差异。MP 的类型和站位是影响生物膜细菌群落结构的重要因素。与海水样本相比，某些优势菌如弧菌科、红杆菌科、黄杆菌科、微菌科和鞘氨醇单胞菌科在 MPs 中得到了富集。其中，弧菌科、红杆菌科和黄杆菌科与石珊瑚组织损伤密切相关，弧菌也是珊瑚白化的主要病原体。此外，在 MPs 生物膜上还检测到假单胞菌和霍乱弧菌。培养后 MPs 的 SEM 图谱可以清楚地观察到棒状细菌和链球菌。本研究可为 MPs 研究珊瑚毒理学提供新方向，为 MPs 毒理学研究提供基础数据。
