Microbial Bioremediation of Heavy Metals: Emerging Trends and Recent Advances

Significant amounts of heavy metals are being added into the soil and effluents each and every day due to enhanced industrialization and other anthropocentric activities. Many heavy metals are even non-degradable in nature and hence once released into the environment remain in circulation. Upon increased concentrations beyond the threshold limit, these heavy metals may not only result in chronic and lethal diseases in humans but also affect the animal and plant metabolism. Many of the physico-chemical methods employed as of today such as electrochemical treatment, ion exchange, precipitation and reverse osmosis for heavy metal removal from waste streams have not been proved cost effective, therefore a biological approach could prove as an alternative remediation technology for heavy metals contamination. Microbes have evolved mechanisms such as active efflux or sequestration with proteins or insoluble compounds through which they may resist, detoxify or metabolize these heavy metals. Current review highlights the recent advancements made in understanding the heavy metals-microbes interaction and applications thereof in heavy metal remediation.