Efficiency of Rhizospheric Bacteria in the Production of Ammonium in the Presence of Arsenic

Abstract

The aim of the present study was to isolate rhizospheric bacteria and to evaluate in vitro their arsenic tolerance and ammonium production. Bacteria were isolated from arsenic-contaminated environments, tolerance to the highest arsenic concentration was evaluated in vitro and ammonium production capacity was determined. A total of 6 rhizospheric bacterial strains were able to tolerate 500 mg/L AsCl2 and simultaneously were found to produce ammonium ion concentrations of 0.87 to 1.3 mg/L. The ability of rhizospheric bacteria to tolerate high concentrations of arsenic makes them direct candidates for contributing to remediation of arsenic-polluting environments and the ability to produce ammonium is an indirect strategy to promote plant growth and promote plant tolerance to toxic metals.