Isolation and characterization of a fungus able to degrade pyrethroids and 3-phenoxybenzaldehyde

Abstract

Fungal strain HU, isolated from activated sludge and identified as a member of the genus Cladosporium based on morphology and sequencing of 28S rRNA, was shown to degrade 90% of fenvalerate, fenpropathrin, β-cypermethrin, deltamethrin, bifenthrin, and permethrin (100 mgL(-1)) within 5 days. Fenvalerate was utilized as sole carbon and energy source and co-metabolized in the presence of sucrose. Degradation of fenvalerate occurred at pH 5-10 at 18-38°C. The fungus first hydrolyzed the carboxylester linkage to produce α-hydroxy-3-phenoxy-benzeneacetonitrile and 3-phenoxybenzaldehyde, and subsequently degraded these two compounds with a q(max), K(s) and K(i) of 1.73 d(-1), 99.20 mgL(-1) and 449.75 mgL(-1), respectively. Degradation followed first-order kinetics. These results show that the fungal strain may possess potential to be used in bioremediation of pyrethroid-contaminated environments.