From Agricultural Allies to Environmental Concerns: Unraveling the Microbial Detoxification of Benzimidazole Fungicides

Abstract

Benzimidazole fungicides (MBCs) are widely used for crop disease control, but their persistence and residues in soil, water, and agricultural products have raised increasing ecological and health concerns. This review summarizes the environmental fate, nontarget toxicity, and degradation strategies of representative MBCs, with particular emphasis on microbial detoxification. Reported degraders, including Rhodococcus spp. and Bacillus spp., as well as related functional communities, can efficiently transform typical MBCs under laboratory conditions. Microbial degradation generally proceeds through carbamate-bond hydrolysis, hydroxylation, ring cleavage, and further mineralization, mediated by enzymes such as amidohydrolases, hydroxylases, dioxygenases, esterases, and monooxygenases. Structural substituents strongly influence degradation routes and metabolite profiles. Remaining challenges include incomplete pathway elucidation, uncertain metabolite toxicity, and limited field stability of degraders. This review provides a mechanistic basis for developing sustainable bioremediation strategies for MBC residues.