Biotransformation of dieldrin by the marine fungus Penicillium miczynskii CBMAI 930

• This paper describes the use of marine-derived fungi isolated from marine sponges in the biotransformation of dieldrin.
• Penicilliun miczynskii CBMAI 930 catalyzed the biotransformation of dieldrin in high conversion rates.
• Marine fungi have potential for bioremediation processes of organic pollutants.

The marine-derived fungi Aspergillus sydowii CBMAI 935, A. sydowii CBMAI 933, Penicillium miczynskii CBMAI 930 and Trichoderma sp. CBMAI 932 isolated from the marine sponges Geodia corticostylifera and Chelonaplysylla erecta were cultivated in the presence of the pesticide dieldrin at different concentrations (25, 50 and 75 mg L−1). All fungal strains were able to grow in the presence of this pesticide; however, P. miczynskii showed the highest tolerance to dieldrin and was selected for further experiments. P. miczynskii CBMAI 930 catalyzed the biotransformation of dieldrin (50 mg L−1) with high conversion rates (90%) after 14 days in liquid medium. Kinetic studies showed that 70% of dieldrin was biotransformed after 4 days of incubation. A method validation was performed using five samples in which the fungi P. miczynskii CBMAI 930 was cultivated showing a recovery of 86% and standard deviation of 3%. This is the first report of dieldrin biotransformation by the marine fungi P. miczynskii CBMAI 930. Results suggest that P. miczynskii is a prospective strain for bioremediation of dieldrin.