Biochemical process and functional genes of arsenic accumulation in bioremediation: agricultural soil

Abstract

This paper offers a critical analysis of the arsenic-accumulating, transforming bacteria and their potential use and effect in remediating agricultural soil. Given the worldwide presence, sources, types, and pathways of arsenic, accumulating, and transforming bacteria, and the effect of arsenic contamination on plant and agricultural soil were studied. Diverse published studies have emphasized arsenic characteristics and effects on soil. In this study, we emphasized the biochemical process and the bioremediation mechanism of arsenic contamination. The method used to isolate and identify arsenic-resistant bacteria was also described. This paper provided an overview of the information about the contamination of arsenic, the effect of its accumulation in agricultural fields, and which bacteria are used to metabolize arsenic in soil. Various types of microbes, including Exiguobacterium, Aeromonas, Bacillus, Pseudomonas, Escherichia, and Acinetobacter, metabolize the activity of inorganic arsenic to generate their energy. The bacterial ars operon consists of three to five genes that are located in plasmids. These genes are involved in oxidation, reduction, methylation, or demethylation in the arsenic transformation process in bioremediation. For example, in arsenic (V) reduction, two microbial pathways known are the detoxification pathway arsC genes negotiate and the respiratory pathway arsA genes negotiate. Further, this paper demonstrates briefly the sources of arsenic contamination and its effect on plants and soils. It has been found that certain microbes' genes facilitate the reduction and oxidization in arsenic toxicity and have some bioremediation capacity to reduce and immobilize the arsenic contamination in agricultural soil.