Characteristics Of Soil Microbial Populaion Of Mercury Methylation Microorganisms In Rice Paddies In Typical Mercury Mining Area Of China

Mercury,as a global pollutant,is a much more complex and serious challenge to deal with pollution than conventional contaminants.At present,China is the most drastic mercury-producing countries,especially in the mercury mining area,because mercury mining and related industrial activities will cause serious environmental pollution.Mercury in the natural environment is mainly in the form of inorganic mercury,and it can build another more toxic mercury form melthylmercury through biological and abiotic ways.Methylmercury has a strong neurotoxicity and bioaccumulation,causing great harm to human health.Therefore,it is very important to study the process of mercury methylation,especially the mechanisms of microbial methyl mercury methylation.In this work,mercury-methylating microbes were obtained with hgcA molecular biomarkers from 45 paddy soil samples in a Guizhou Province,a Hunan Province and a Shanxi Province.The microbial community compositions of rice paddies in mercury mining area were investigated by sequencing methods.The sequencing results showed that hgcA microbes in paddy soils were potentially related to Proteobacteria,Euryarchaeota,Chloroflexi,and two unknown groups.Compared the relative abundance of hgcA gene-related microbes in three mercury mines,the advantages of Guizhou were the Euryarchaeota,while the dominant phylum of Hunan and Shaanxi were Proteobacteria.Furtherrmore,the correlation between microbial community diversity and environmental factors in rice paddies between the typical mercury mining areas of China.The results indicated pH and organic matter dominated the microbial community diversity.