Biodegradation of the Pyrethroid Pesticide Esfenvalerate by Marine-Derived Fungi.

Abstract

Esfenvalerate biodegradation by marine-derived fungi is reported here. Esfenvalerate (S,S-fenvalerate) and its main metabolites [3-phenoxybenzaldehyde (PBAld), 3-phenoxybenzoic acid (PBAc), 3-phenoxybenzyl alcohol (PBAlc), and 2-(4-chlorophenyl)-3-methylbutyric acid (CLAc)] were quantitatively analyzed by a validated method in triplicate experiments. All the strains (Penicillium raistrickii CBMAI 931, Aspergillus sydowii CBMAI 935, Cladosporium sp. CBMAI 1237, Microsphaeropsis sp. CBMAI 1675, Acremonium sp. CBMAI 1676, Westerdykella sp. CBMAI 1679, and Cladosporium sp. CBMAI 1678) were able to degrade esfenvalerate, however, with different efficiencies. Initially, 100mgL(-1) esfenvalerate (Sumidan 150SC) was added to each culture in 3% malt liquid medium. Residual esfenvalerate (64.8-95.2mgL(-1)) and the concentrations of PBAc (0.5-7.4mgL(-1)), ClAc (0.1-7.5mgL(-1)), and PBAlc (0.2mgL(-1)) were determined after 14days. In experiments after 7, 14, 21, and 28days of biodegradation with the three most efficient strains, increasing concentrations ofthe toxic compounds PBAc (2.7-16.6mgL(-1), after 28days) and CLAc (6.6-13.4mgL(-1), after 28days) were observed. A biodegradation pathway was proposed, based on HPLC-ToF results. The biodegradation pathway includes PBAld, PBAc, PBAlc, ClAc, 2-hydroxy-2-(3-phenoxyphenyl)acetonitrile, 3-(hydroxyphenoxy)benzoic acid, and methyl 3-phenoxy benzoate. Marine-derived fungi were able to biodegrade esfenvalerate in a commercial formulation and showed their potential for future bioremediation studies in contaminated soils and water bodies.