Microbial phytoremediation of contaminated soils irrigated with industrial effluents: a soil health perspective

Abstract

Industrialization, urbanization, and poor farming practices have led to major problems regarding potentially toxic elements (PTEs). PTEs in industrial effluents adversely affect water quality, soil, plants, and aquatic life, and ultimately cause severe health problems in humans. Several strategies have been utilized to overcome this serious environmental issue. The conventional methods most commonly used for this purpose are expensive and not environmentally friendly. Phytoremediation is a very cost-effective and eco-friendly strategy where researchers are focusing their efforts nowadays. This technique utilizes plants to remove PTEs from the soil. The efficacy of phytoremediation is enhanced by the microorganisms in the rhizosphere, where microbes utilize root exudates as their energy source, which in turn remove or solubilize PTEs from the soil. Microbes have adopted several mechanisms that directly and/or indirectly assist plants in resisting PTE stress. These mechanisms include biosorption, bioaccumulation, efflux systems, enzymatic detoxification, siderophore production, biosurfactants, extracellular sequestration, intracellular sequestration, ACC-deaminase, IAA production, and phytohormone production. Plant–microbe interaction is one of the most successful approaches that not only aids in remediating PTEs from the soil but also assists plant development. The efficiency of microbial activity could be enhanced by inserting PTE resistance genes so that genetically engineered microbes (GEMs) work more efficiently to remove PTEs from soil or water. The current review addresses the deleterious effects of PTEs on living organisms and discusses possible cost-effective and eco-friendly microbial-assisted phytoremediation strategies to remove PTEs from soil contaminated with industrial effluents.