Deciphering microbial approaches for heavy metal removal: an overview on their mechanisms, innovations and future horizons.

Heavy metal contamination of water and soil poses grave issues for the environment as well as human health owing to its high toxicity, persistence in the environment, and probable bioaccumulation. Conventional methods, including chemical leaching, membrane filtration, etc., are advantageous but produce secondary pollutants. However, microbial bioremediation appears to be one of the most promising eco-friendly techniques that involves bacteria, fungi and algae. In addition to that, indigenous microbes are more adaptive to polluted environments, thereby ensuring enhanced bioremediation efficacy. Basic microbial mechanisms of biosorption, bioaccumulation, extracellular precipitation, and biotransformation that stabilize and detoxify heavy metals have also been outlined. This study also hypothesizes the integration of genetic engineering and nanotechnology in heavy metal bioremediation for large-scale applications. Finally, the review addresses the existing challenges and limitations, such as bioavailability of metals and complex pollutant interactions and emphasizes the need for further research for scale expansion and to conquer environmental constraints.