Study On The Characteristics And Application Of Arsenic Resistant Bacteria In High Arsenic Region

Arsenic pollution is one of the most concerned problems in water and soil environment.The indigenous microorganisms in the high arsenic region regulate and control the migration and transformation of arsenic in the water and soil environment of the mainland.It is of great significance to identify the characteristics of indigenous microorganisms for controlling pollution.It is an important research direction in recent years to use the unique biological properties of indigenous microorganisms to direct the remediation of soil and water environment and to make use of its characteristics to prepare environmental friendly materials in recent years.The main contents of this paper are as follows: the arsenic reducing bacteria Pantoea sp.IMH obtained by the high arsenic region was used to study the effects of arsenic resistance and organic pollutants on the migration and transformation of arsenic in water and soil.The study on the biosynthesis of composite metal nanoparticles by the Pantoea sp.IMH,which was discovered by chance,can be used to reduce the properties of precious metal ions,and to explore the application of the composite metal nanoparticles synthesized by microbes.The main conclusions obtained are as follows:(1)Microbial activity has a more significant effect on arsenic dissolution than non microbial activities,and increases the risk of arsenic contamination in the environment.Glyphosate can extract more adsorptive arsenic than dicamba,and glyphosate has more serious effects on arsenic pollution in water and soil than dicamba.Under aerobic conditions,glyphosate had no significant effect on the function of arsenic reduction gene in IMH,but under anaerobic conditions,the arsenic reduction gene of ANA-3 was inhibited.Dicamba had a strong inhibitory effect on arsenic reduction and growth behavior of IMH,but had little effect on ANA-3.(2)Biosynthesis of Au-Ag,Ag-Se,Au-Se and Au-Pd nanoparticles was achieved by strain Pantoea sp.IMH.The results show that the synthesis of Au-Ag and Ag-Se is the best,while the synthesis of Au-Pd and Au-Se nanoparticles is relatively general.(3)Silver selenide nanoparticles were synthesized by strain Pantoea sp.IMH,and the positive dye methylene blue,neutral dye indigo and negative dyestuff yellow were adsorbed under three pH conditions.The results showed that the adsorption process of the silver selenide nanoparticles on the three dyes was more in line with the Langmuir model,which belonged to monolayer adsorption and had a better adsorption and removal effect on the positive and neutral dyes.The adsorption of positive methylene blue reached 182mg/g at pH=9,and there was no obvious adsorption for negative dyes.In this study,the effects of arsenic reducing bacteria and organic pollutants on the migration and transformation of arsenic in water and soil were preliminarily explored.It provided direct evidence for microbial participation in the biogeochemical cycle of arsenic,and tried to cut off the microbial pathway of As(V)being reduced to As(III),providing some scientific references forthe further study of the remediation of arsenic pollution in water and soil.At the same time,the biosynthesis method of precious metal nanoparticles is expanded,and the application of silver selenide nanoparticles is explored.