Microbial Bioremediation of Heavy Metals-Process, Challenges and Future Aspect: A Comprehensive Review

Heavy metals have a prominent share as environmental pollutants owing to their toxicity, persistence in the environment and bio-accumulative nature. Cadmium (Cd), Copper (Cu), Lead (Pb), Selenium (Se) and Zinc (Zn) are few heavy metals that humans are primarily exposed to. These metals constitute a concern to human health because they can interfere with the operation of essential cellular components. The heavy metals can be created by nature through the weathering of metal bearing rocks and volcanic eruptions or by humans through mining and different industrial and agricultural operations. These heavy metals can be found in the soil, water and air. Heavy metals in the soil pose a significant danger to food security since their contamination poses risks to humans and the ecosystem by drinking contaminated groundwater, direct ingestion or the food chain and a decrease in food quality.

Present physical and chemical heavy metal remediation technologies, such as electrochemical treatment, ion exchange, precipitation and reverse osmosis are not cost effective, feasible time efficient or environmentally friendly; therefore, a biological approach could serve as an alternative heavy metal remediation technology.

By utilizing the innate biological capabilities of microorganisms, bioremediation appears as an efficient and environmentally acceptable approach of cleaning up areas that have been contaminated with heavy metals. This review examines the hazardous effects of heavy metal contamination and the environmental remediation techniques employed by microbes. This article examines the environmental impacts of heavy metals and how they can be efficiently remedied by the use of microorganisms.

The purpose of this review article is to highlight the significance of modern biotechnological processes and techniques for improving the ability of microbes to degrade heavy metals at a faster rate and to bring the major highlights of review articles in a more comprehensive manner. In this study, new breakthroughs in microbial bioremediation for the removal of heavy metals from the environment are discussed, along with their potential advantages and drawbacks.