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

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, beta-cypermethrin, deltamethrin, bifenthrin, and permethrin (100 mg L-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 degrees C. The fungus first hydrolyzed the carboxylester linkage to produce alpha-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 mg L-1 and 449.75 mg L-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. (C) 2011 Elsevier Ltd. All rights reserved.