Roles of mycorrhizal fungi in phytoremediation of contaminated eco-systems

Abstract

ABSTRACT Accumulation and concentration of contaminants in the soil have long been a byproduct of industrialisation and urbanisation, and which has become a primary environmental concern. Mitigation of soil pollutants using chemical procedures and their long-term application have originated a detrimental impact on all ecosystems. The application of green technologies such as bioremediation to solve environmental risk factors contributes to a long-term preservation of the fauna and flora, ensuring at the same time human health and well-being. Bioremediation refers to naturally occurring or any introduced microorganisms that break down or sequestrate environmental contaminants to clean the soil from pollutants. This review discusses different mechanisms of mycorrhizae related to the soil habitats and the factors affecting their functions in removing contaminants from the soil itself. The mycorrhizae remediate the soil contaminants either by phytoremediation (arbuscular mycorrhizal fungi [AMF]) or degradation (ectomycorrhizae and ericoid mycorrhizae). AMF are involved in remediating the non-degradable pollutants (heavy metals and metalloids), while ectomycorrhizae and ericoid mycorrhizae are preferred to remediate polar and non-polar organic pollutants in soil using mycorrhizal enzymes. The efficiency of the bioremediation depends mainly on factors such as the species of AMF involved, host plant species, type and dose of the contaminants, the methods used in bioremediation, the soil, and environmental conditions. Combining bioremediation with advanced technologies like metagenomics, metatranscriptomics, and metabolomics accelerates the remediation processes that neutralise the environmental toxicity generated through present and future anthropogenic activities.