Bioremediation of chromium and arsenic-contaminated soil using the potential of fungi for a healthy ecosystem

Heavy metal contamination has become a major environmental concern and research topic for scientists and scholars. Chromium and arsenic are well-known pollutants with serious health effects. They are discharged into the environment by both natural and artificial sources and are highly toxic even at low concentrations; non-biodegradable and can persist in the environment for long periods. Arsenic exposure can lead to serious health issues such as nausea, vomiting, skin lesions, and heart diseases, whereas health problems like skin irritation, emphysema, and headache arise due to chromium exposure. Therefore, there is a need to mitigate the increasing pollution caused by these heavy metals. Bioremediation is a microbe-assisted technology that deals with elevated levels of heavy metals. Mushrooms are a powerful weapon in the fight against these metals. They are natural decomposers containing various extracellular enzymes. Fungi use a variety of mechanisms for bioremediation and can be used in a wide range of applications. The mechanisms involved in bioremediation are biosorption, bioaccumulation, chelation, and biotransformation. In future perspectives, there is a need to conduct molecular-level studies to identify the genes involved and study the metabolic pathways and enzymes which are employed in bioremediation. This review focuses on the different sources of chromium and arsenic emissions, their toxicity and associated health issues, various mechanisms of bioremediation, and future aspects.