Fungi-Enhanced Phytoremediation: A Natural Solution for Mercury-Contaminated Soil
- Marc Violo
- Mar 30
- 2 min read
Mercury (Hg) contamination is a severe environmental issue, especially in artisanal gold mining areas. Tailings from these sites frequently contain dangerously high mercury levels, presenting significant health risks to local populations and ecosystems. For instance, tailings in Bunut Village, Lampung Province, Indonesia, showed mercury concentrations as high as 42.61 ppm, vastly exceeding Indonesia's safety threshold of 0.05 ppm.
Why Phytoremediation Matters?
Phytoremediation leverages plants' innate abilities to absorb and store heavy metals, providing a sustainable method to mitigate soil contamination. Among native plants suited for phytoremediation, Swietenia macrophylla (Mahogany) is particularly valuable due to its proven adaptability and resilience in polluted environments, making it ideal for rehabilitating mercury-contaminated lands.
Enhancing Remediation with Arbuscular Mycorrhizal Fungi
Research has shown that combining phytoremediation plants with beneficial fungi, specifically Arbuscular Mycorrhizal Fungi (AMF), significantly enhances remediation outcomes. AMF form symbiotic associations with plant roots, increasing nutrient uptake, tolerance to toxicity, and overall growth in polluted conditions. These characteristics make AMF essential allies in enhancing phytoremediation efforts.
A study conducted by researchers at Gadjah Mada University and the University of Lampung in Indonesia tested different AMF strains inoculated in S. macrophylla plants growing in mercury-contaminated tailings. Their research showed that Mahogany trees inoculated with the fungus Acaulospora sp. 4 absorbed 28.65% more mercury than plants without fungal inoculation. Additionally, these plants achieved the highest AMF colonization rate of 16.67%, indicating a robust symbiotic relationship facilitating greater mercury absorption. Mercury content in the leaves of these plants reached 4.15 ppm, significantly higher than non-inoculated controls, underscoring the effectiveness of fungi-enhanced phytoremediation (Jayani et al., 2025).
How Fungi Facilitate Remediation
Arbuscular Mycorrhizal Fungi improve mercury remediation through several interconnected mechanisms. Firstly, fungi immobilise mercury in soil through the production of compounds like glomalin. Secondly, mercury accumulates within fungal structures, including vesicles and arbuscules, effectively reducing its bioavailability. Lastly, the fungal network extends the root's absorptive capacity, allowing more mercury to be taken up by plants from contaminated soil (Jayani et al., 2025).
Practical Considerations and Future Directions
While the potential of AMF-assisted phytoremediation is promising, it requires careful management. Regular harvesting of mercury-rich plant biomass is crucial to avoid re-contamination through leaf fall. Additionally, harvested plant matter must be safely processed or disposed of to ensure mercury does not re-enter the environment. Moving forward, continued research is essential to refine fungal selection, plant combinations, and practical management strategies tailored to specific contaminated sites.
Ultimately, fungi-plant partnerships offer a promising, cost-effective, and sustainable solution to the ongoing challenge of mercury contamination, especially in regions heavily impacted by artisanal and illegal mining.