Efficient removal potential of Microbacterium sp. strain 1S1 against arsenite isolated from polluted environment

Abstract

A multiple metal resistant Microbacterium sp. strain 1S1, tolerated arsenite and arsenate upto 75 and 520 mM, was isolated from industrial wastewater. The arsenite surface adsorption and uptake into the bacterial cells, exposed to 15 mM arsenite, were confirmed through Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), and Fourier-transform infrared spectroscopy (FTIR) analyses. The cell physiology of strain 1S1 altered in arsenite exposure and the percent increase in GSH/GSSG ratio and NPSHs concentration was up to 40.0 and 78.50%. Furthermore, 240% increase in catalase provided evidence that arsenite induces hydrogen peroxide mediating oxidative stress. The bacterial cells growing in a rich medium with 15 mM arsenite were able to oxidize 98% arsenite after 96 h of incubation, and the inactivated biomass of the bacterium at 1 g per liter removed 99% of 15 mM arsenite after 10 h incubation. The harboring of multiple resistance strategies and appreciable arsenic oxidizing potential make strain 1S1 an impending foundation for green chemistry to exterminate environmental arsenite.

Keywords

• Arsenic
• Microbacterium sp. 1S1
• As-resistance
• Antioxidant enzymes
• Bioremediation