MICROBIAL-ASSISTED PHYTOSTABILIZATION OF HEAVY METAL CONTAMINATED SOIL

Abstract

Heavy metal contamination resulting from industrial activities, mining, agriculture, and urbanization poses serious risks to ecosystems and human health. Toxic metals such as cadmium (Cd), lead (Pb), mercury (Hg), chromium (Cr), and nickel (Ni) persist in soils, accumulate in food chains, and disrupt ecological balance. Traditional remediation approaches, including soil excavation and chemical treatments, are often expensive, environmentally unsustainable, and can degrade soil quality.

Phytoremediation, especially phytostabilization, offers a sustainable alternative by employing plants and their associated rhizobacteria to immobilize metals in the rhizosphere, thereby reducing metal mobility, limiting groundwater contamination, and minimizing transfer through the food chain. Metal-tolerant rhizobacteria enhance this process by producing siderophores, exopolysaccharides, biofilms, and phytohormones, which aid in metal immobilization, improve plant tolerance, and maintain soil fertility. They also suppress pathogens and enhance nutrient uptake, supporting plant growth in contaminated soils.

Despite these benefits, challenges such as low biomass production, heterogeneous soil conditions, and uncertainties regarding long-term effectiveness restrict large-scale application. Future research should aim to optimize plant–microbe interactions and clarify their mechanisms under varied environmental conditions. Rhizobacteria-assisted phytostabilization thus represents an eco-friendly and sustainable strategy for mitigating heavy metal pollution while promoting soil restoration and enhancing agricultural productivity.