Mycoremediation is a form of bioremediation in which fungi-based remediation methods are used to decontaminate the environment. Fungi have been proven to be a cheap, effective and environmentally sound way for removing a wide array of contaminants from damaged environments or wastewater, including heavy metals, organic pollutants, textile dyes, leather tanning chemicals, petroleum fuels, polycyclic aromatic hydrocarbons, pharmaceuticals and personal care products, and pesticides and herbicides in land, freshwater, and marine environments. The approach includes several mechanisms: biosorption for binding contaminants to fungal biomass; biodegradation for breaking down organic pollutants through enzymatic action; bioaccumulation for concentrating toxins within fungal tissues; and biotransformation for converting contaminants into less harmful forms. These processes can also yield valuable byproducts such as enzymes like laccase or edible and medicinal mushrooms, making the remediation process even more profitable.
This remediation strategy is favoured for sites contaminated with persistent organic pollutants and heavy metals where traditional methods prove too costly or environmentally disruptive. Mycoremediation is a cheaper method of remediation and doesn't usually require expensive equipment, which is why it is often used in small-scale applications such as mycofiltration of domestic wastewater and industrial effluent filtration. Mycoremediation is particularly suitable where in-situ treatment is desirable and where biological processes can be sustained over time, such as in contaminated soils, former industrial sites, or areas with diffuse pollution. In-situ application of fungi is advantageous due to the limited disturbance that this approach induces to the polluted site . However, it is not ideal for sites requiring immediate decontamination, highly acidic or alkaline conditions without amendment, or where rapid regulatory compliance is mandated.
The advantages of mycoremediation include its cost-effectiveness, environmental sustainability, and versatility across diverse contaminants. Many fungi are hyperaccumulators, able to concentrate toxins in their fruiting bodies for later removal, with hyperaccumulation occurring via biosorption on the cellular surface where metals enter the mycelium passively with very little intracellular uptake . Thanks to their non-specific enzymes, fungi are able to break down many kinds of substances including pharmaceuticals and fragrances that are normally recalcitrant to bacteria degradation . The most commonly used fungi are white rot fungi, which, thanks to their extracellular ligninolytic enzymes like laccase and manganese peroxidase, are able to degrade high quantities of such components. Yet, limitations include the time-consuming nature of the process, with removal of contaminants rarely reaching 100%, and the bioavailability of the pollutant and soil matrix influencing the final treatment result. Additionally, one major disadvantage of fungi in in-situ application is competition of the bioremediatory fungus with indigenous microbial communities, particularly bacteria, which renders the prospects of applications limited, challenges with fungal establishment in contaminated environments, and the need to assess toxicity or genotoxicity of mushrooms if cultivated on industrial wastes for bioremediation purposes. Regulatory concerns may arise around the inadvertent introduction of non-native fungal species to environments.
Implementation requires appropriate fungal species selection, site preparation, and environmental monitoring. Time, pH, temperature, concentration of heavy metals, dose of fungal biomass, and shaking rate are the most influencing factors that affect bioremediation and vary with characteristics of the fungi and nature of the contaminants. The method aligns well with other remediation approaches and fungi do not work in isolation when remediating a contaminated site, but rather in synergy with plants and bacteria and other organisms. The greatest challenge for mycoremediation is scaling up the proof-of-concept applications that have been demonstrated for years . Overall, mycoremediation offers a flexible, ecologically conscious option for environmental restoration, especially where long-term environmental and social benefits are prioritised.