Use of heavy metals resistant bacteria-a strategy for arsenic bioremediation

A large number of industries release their untreated wastes in the environment causing an increase in the concentration of toxic pollutants including heavy metal ions in ground and drinking water which is above the WHO limit. The presence of toxic pollutants in the industrial wastes pollutes our environment. Arsenic (As) is a ubiquitous toxic metalloid. Its amount varies in different parts on the earth, and its concentration is increasing in our environment day by day both by natural and anthropogenic activities. It is found in two forms; one is arsenate (As⁵⁺) and other is arsenite (As³⁺) and the latter is more toxic due to high mobility across the cell membrane. The long-term use of arsenic-containing water causes arsenicosis. High arsenic consumption, revealed by skin harms, color change, and spots on hands and feet, may cause skin cancer and affect lungs and kidneys. Hypertension, a state of high blood pressure, and lack of insulin which causes diabetes and many other disorders which relate to reproduction are the consequences of arsenic contamination. Several methods have been employed to decontaminate arsenic pollution, but the bioremediation by using biomass of bacteria, algae, fungi, and yeasts is the most compromising approach and has gained much attention from researchers in the last few decades. The microbial detoxification of arsenic can be achieved by reduction, oxidation, and methylation. High bioremediation potential and feasibility of the process make bacteria an impending foundation for green chemistry to exterminate arsenic in the environment.