Biodegradation of Chlorpyrifos by Whole Cells of Marine-Derived Fungi Aspergillus sydowii and Trichoderma sp

Abstract

This paper describes the screening of the growth of seven marine-derived fungi strains in the presence of chlorpyrifos in solid medium. The strains that showed best growth were A. sydowii CBMAI 935 and Trichoderma sp. CBMAI 932. Biodegradation reactions were performed in 10, 20 and 30 d in liquid medium containing commercial chlorpyrifos and mycelia from the selected strains. In 30 d, A. sydowii CBMAI 935 and Trichoderma sp. CBMAI 932 were able to degrade on average 63% and 72% of chlorpyrifos, respectively, and reduce the concentration of 3,5,6-trichloro-2-pyridinol, the metabolite formed by the enzymatic hydrolysis of chlorpyrifos. In 30 d, A. sydowii CBMAI 935 and Trichoderma sp. CBMAI 932 could use chlorpyrifos as sole source of carbon with low biodegradation percentages, 24% and 5%, respectively. Spontaneous hydrolysis was evaluated in malt medium, with the complete disappearance of chlorpyrifos. In distilled water, 61% of chlorpyrifos was hydrolyzed in 30 d.