Isolation and Molecular identification of native As-resistant bacteria: As(III) and As(V) removal capacity and possible mechanism of detoxification

Abstract

The study of arsenic resistant microorganisms with high arsenic removal capacity is fundamental for the development of economically sustainable technologies for the treatment of water contaminated with this metalloid. In this work, the isolation and identification of 4 native strains was carried out.: Rhodococcus gordoniae, Microbacterium hydrocarbonoxydans, Exiguobacterium indicum and Pseudomonas kribbensis . R.gordoniae was identified as the bacterium with the highest growth capacity in both As(III) and As(V). E.indicum removed about 74.8% of Arsenate, As(V), and 61.7% of Arsenite , As(III), while R.gordoniae removed about 81.6 % of As(III), and 77.2% of As(V), while that M.hydrocarbonoxydans was able to remove up to 79.9% of As(III) and 68.9% of As(V). Finally, it was observed that P. kribbensis removed about 80.2% of As(V). This study also contributes to the possible detoxification mechanisms employed by these bacteria, the knowledge of which could be crucial in the successful implementation of in situ bioremediation programs.