珠江河口滩涂沉积物中可培养细菌多样性及微塑料降解功能菌资源的挖掘

Diversity of culturable bacteria in mudflat sediments of the Pearl River Estuary and exploitation of microplastic-degrading bacterial resources

摘要:

目的 探究广东珠江河口滩涂沉积物中的可培养细菌多样性，并挖掘具有微塑料降解功能的菌株资源。方法 使用5种培养基对微生物进行分离与纯化，采用MEGA-X进行系统进化分析。利用聚对苯二甲酸乙二醇酯(polyethylene terephthalate, PET)培养基筛选具有PET微塑料降解功能的菌株，并对相关基因进行功能注释。结果 共分离得到265株细菌，分布于4门32科71属。其中，假单胞菌门(Pseudomonadota) 168株，占比63.40%；放线菌门(Actinomycetota) 38株，占比14.34%；芽孢杆菌门(Bacillota) 31株，占比11.70%；拟杆菌门(Bacteroidota) 28株，占比10.56%。基于16S rRNA基因序列的同源性分析，推测其中59株菌株可能为潜在新物种。同时，筛选获得1株具有潜在PET降解功能的菌株。结论 本研究成功获得广东珠海香洲区滩涂特有的微生物菌株资源，并筛选得到1株能以PET作为唯一碳源进行生长的细菌。

关键词:珠江河口;滩涂沉积物;细菌分离;微塑料降解

Abstract:

Objective To explore the diversity of culturable bacteria in the mudflat sediments of the Pearl River Estuary in Guangdong Province and to mine strain resources capable of degrading microplastics from these sediments.Methods Five media were used for microbial isolation, and phylogenetic analysis was performed by MEGA-X software. The polyethylene terephthalate (PET) medium was selected to screen PET microplastic-degrading strains, and then gene function annotation was performed.Results A total of 265 bacterial strains belonging to 71 genera, 32 families of 4 phyla were isolated, including 168 (63.40%) strains of Pseudomonadota, 38 (14.34%) strains of Actinomycetota, 31 (11.70%) strains of Bacillota, and 28 (10.56%) strains of Bacteroidota. Based on the homology of 16S ribosomal RNA (16S rRNA) gene sequences, it was hypothesized that 59 of these strains might be potential new species. From the isolated strains, one PET microplastic-degrading strain was screened.Conclusion This study successfully obtained unique microbial resources from the tidal flats of Xiangzhou District, Zhuhai City and one strain capable of degrading PET and using PET as the sole carbon source.

Key words:Pearl River Estuary;mudflat sediments;bacterial isolation;microplastic degradation