Ganoderma lucidum Immobilized on Wood Demonstrates High Persistence During the Removal of OPFRs in a Trickle-Bed Bioreactor

Emerging pollutants such as organophosphate flame retardants (OPFRs) pose a critical threat to environmental and human health, while conventional wastewater treatments often fail to remove them. This study addresses this issue by evaluating the bioremediation potential of white-rot fungi for the removal of two OPFRs: tris(2-chloroethyl) phosphate (TCEP) and tributyl phosphate (TBP). Three fungal species-Ganoderma lucidum, Trametes versicolor, and Phanerochaete velutina-were screened for their degradation capabilities. Among these, G. lucidum and T. versicolor demonstrated removal efficiencies exceeding 99% for TBP, while removal rates for TCEP were significantly lower, with a maximum of 30%. The exploration of the enzyme role showed that cytochrome P450 is involved in the degradation while the extracellular laccase is not involved. Continuous batch experiments were performed using a trickle-bed reactor (TBR) operating under non-sterile conditions, a setting that closely resembles real-world wastewater treatment environments. G. lucidum was immobilized on oak wood chips, and the removal efficiencies were measured to be 85.3% and 54.8% for TBP and TCEP, respectively, over 10 cycles. Microbial community analysis showed that G. lucidum remained the dominant species in the reactor. These findings demonstrate the efficacy of fungal-based trickle-bed bioreactors, offering a sustainable and efficient alternative for addressing environmental pollution caused by highly recalcitrant pollutants.