微塑料对近岸多环芳烃降解菌群结构及其降解能力的影响

近海岸微塑料的污染问题日益突出,对周围生态环境造成了严重的影响.微塑料研究主要集中于微塑料在生物体内的积累,而有关微塑料对微生物生态的影响研究还很少.本文针对受微塑料影响较严重的近岸环境,从受石油污染的近岸水体中富集驯化得到功能菌群菲降解菌群MB1,探究微塑料对近岸菲降解菌群结构及降解能力的影响.结果表明:微塑料的添加在一定程度上促进菲的降解;SEM扫描电镜分析进一步显示微生物附着在微塑料上并分泌丝状物质;采用Illumina序列分析添加微塑料后菌群结构的变化,发现培养6 d后在有添加微塑料的体系中优势菌属以Glaciecola为主,而未添加的对照组中优势菌属是Rhdovulum,说明微塑料的添加可明显改变降解多环芳烃的菌群结构,进而影响污染物的降解能力.

Effect of microplastic on the community structure and biodegradation potential of PAHs -degrading bacterial consortium in coastal environment

Microplastic pollution has become serious and caused harmful effect in the coastal environment. Most studies have focused on the accumulation of microplastic in the organism through the food chain, while less is known about the impact of microplastic on microbial ecosystem. In this study, the phenanthrene-degrading bacterial consortium MB1 was enriched from oil-contaminated coastal water, where microplastic pollution is a major concern. The impact of microplastic on the microbial community structure and biodegradation potential of phenanthrene-degrading bacteria were investigated. The results show that the addition of microplastic could increase the removal efficiency of phenanthrene. SEM images further show that microplastic surface was covered with filamentous materials, where bacteria can adhere to the microplastic. The impact of microplastic on the community structure was further analyzed by high-throughput sequencing. Glaciecola was the dominant genera in the bacterial community with the addition of microplastic, while Rhdovulum predominated in the control group after 6-day treatment. The results indicate that microplastic could change the community structure of PAHs-degading bacterial consortium, and may affect the biodegradation potential of oil contaminant in the coastal environment.