鄱阳湖南矶山湿地微塑料表面微生物分布特征

Distribution characteristics of microorganisms on microplastic surface in Nanjishan wetland of Poyang Lake

微塑料作为一种新型污染物在全球水生生态系统中普遍存在,其所引起的环境问题已成为近年来研究的热点.选取鄱阳湖南矶山湿地为研究区,湖泊湿地水体和沉积物中微塑料为研究对象,采集水体和沉积物及其中不同类型微塑料样品(薄膜类、碎片类和纤维类),并利用高通量测序技术分析环境中和微塑料表面微生物群落结构和多样性.结果表明,环境中微生物丰富度和多样性与微塑料表面均存在明显差异,沉积物中微塑料表面微生物丰富度和多样性低于周围沉积物.环境中微生物群落结构与微塑料表面不同,鄱阳湖南矶山湿地水体和沉积物中细菌群落主要包括变形菌门(Proteobacteria)、蓝藻门(Cyanobacteria)、拟杆菌门(Bacteroidetes)和放线菌门(Actinobacteria).与沉积物相比,沉积物中微塑料表面变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)相对丰度显著增加.真菌群落主要包括担子菌门(Basidiomycota)、子囊菌门(Ascomycota)和壶菌门(Chytridiomycota).与环境样品相比,微塑料表面担子菌门(Basidiomycota)相对丰度增加.相关性网络分析结果表明,细菌中Geothermobacter、Sulfuricurvum、根瘤菌属(Rhizobacter)、MM2、马赛菌属(Massilia)、Methylotenera、Dongia、Sh765B-TzT-35、薄层菌属(Hymenobacter)是本次实验预测的关键种.本研究可提高对淡水生态系统微塑料污染的认识,并为湖泊环境管理提供理论依据.

Microplastics,as a kind of emerging contaminants,are ubiquitous in aquatic ecosystems worldwide,by which the environmental problem caused has become one important concern in recent years. In this study,to investigate the effect of microplastics on microbial community structure and diversity,different types of microplastics(film,debris and fiber)were collected from the water and sediment of Nanjishan wetland of Poyang Lake,and the extracted DNA were analyzed by high-throughput sequencing compared to those from the surrounding water and sediment. The results showed that the abundance and diversity of microorganisms from microplastics were significantly lower than those from the surrounding water and sediment. For bacteria,Proteobacteria,Cyanobacteria,Bacteroidetes and Actinobacteria are dominant in water and sediment,while the abundance of Proteobacteria and Firmicutes showed an obvious increase on the surface of microplastics. Meanwhile,Basidiomycota,Ascomycota and Chytridiomycota are the dominant fungi in water and sediment,while the sample of microplastics exhibited an increased abundance of Basidiomycota. Correlation network analysis predicted that Geothermobacter, Sulfuricurvum, rhizobia, Rhizobacter, MM2, Massilia, Methylotenera, Dongia, SH765B-TZT-35,Hymenbacter are the key species. This work could provide a better understanding of microplastic pollution in freshwater ecosystem and some theoretical references for lake environmental management.