A comprehensive review on the application of mycoremediation in polychlorinated biphenyls treatment

Abstract

In the last decades, there has been a growing concern regarding the remediation and recovery of polychlorinated biphenyls (PCBs) contaminated sites. The technologies traditionally used are often energy-intensive, resource-heavy, and highly disruptive to the environments being treated. In this context, mycoremediation has emerged as a highly sought-after alternative due to the efficiency of certain fungal strains in achieving high removal percentages. This review provides an overview of mycoremediation strategies for PCB bioremediation. We begin by outlining the ecotoxicological challenges posed by PCB usage and traditional methods employed for remediating contaminated areas. Secondly, we present different approaches to mycoremediation of PCBs. The use of native PCB-degrading fungi shows that some strains belonging to the Penicillium, Fusarium, and Scedosporium genera are capable of removing over 70 % of different PCBs congeners. Alternatively, we discuss using white rot fungi (WRF) due to their potential in transforming PCBs and associated metabolites. Strains belonging to this group, such as Pleurotus pulmonarius, can attain PCBs removal rates above 90 % with a 10.27 % reduction in toxicity. Additionally, cases demonstrating the application of WRF in long-term polluted soil and water are presented as field examples. A trickle bed pilot-scale bioreactor approach using Pleurotus ostreatus obtained an average PCBs removal of 89 ± 9 % for contaminated groundwater. Similarly, microcosm experiments using P. ostreatus and Irpex lacteus removed up to 50.5 % and 41.3 % of PCBs content in long-term contaminated soils, respectively. We also highlight the role of extracellular ligninolytic enzymes, such as lacasses, lignin peroxidases, manganese peroxidase, manganese-independent peroxidase, and internal oxidoreductases in the PCBs metabolism carried out by WRF. Finally, we conclude with a series of factors to consider when implementing these techniques for remediating polluted sites, including up-scaling, current regulations, and combination with other remediation techniques.