Mechanistic insight into microbial mediated heavy metal uptake and tolerance
Heavy metal (HM) contamination has become a critical threat to the agro-environment, impairing soil fertility, reducing crop productivity, and disrupting ecological balance. It often displays stunted growth, chlorosis, root rot, and ultimately death of plants in severe cases. Due to increased anthropogenic activities, HM accumulation in agricultural soils is rising to an extent and thus adversely affecting the crop productivity, soil health, environmental quality and human health therefore; sustainable strategies for remediation are urgently needed. Microbial bioremediation offers a promising solution by employing the natural ability of microorganisms such as phosphate solubilizers, nitrogen fixers as well as potassium solubilizers to detoxify, immobilize, or transform HM into less toxic forms. This review highlights that microbe-based bioremediation is an effective and sustainable approach for removing HM contaminants in agricultural soil. It highlights specific mechanisms employed by microbes including: biosorption, transportation, sequestering, and detoxification that causes immobilization of HMs and reduces their toxic effect. Furthermore, this review also discusses how integrating advance biotechnological tools with microbial remediation strategies, have the potential to enhance sustainability of agricultural systems. Despite the key advantages, optimizing microbial efficiency for bioremediation still remains a major challenge. Future research focuses on integration of advanced biotechnological interventions, including gene editing, CRISPR-Cas, and improved microbial formulations, to enhance the efficiency and resilience of remediation strategies.