Molecular Characterization of Monocrotophos Hydrolyzing Soil Fungal Strain Penicillium aculeatum ITCC 7980.10

Abstract

A B S T R A C T Pesticides poses great threat to the environmental sustainability by affecting its microbial flora and fauna. Fungi are well known for the secretion of extracellular hydrolases for the degradation of these hazardous chemicals from its ambient environment. Hydrolase secreting soil fungi Penicillium aculeatum ITCC 7980.10 was selected for the study of its monocrotophos degrading efficiency under in vitro conditions in phosphorus free liquid culture medium. Fungal strain was molecularly characterized by 18S rDNA analysis as Penicillium aculeatum JQ660374. Monocrotophos degrading efficiency of the isolate was studied under optimum conditions each, at an interval of 5 days for 15 days incubation period. The isolated strain possessed meagre extracellular phosphatase activity 28.33 ± 0.40 U which resulted in the formation of 614.62 ± 0.38 µg ml -1 inorganic phosphates. Degradation process was studied by spectrophotometric analysis at 254nm, HPTLC and FTIR. Spectrophotometric analysis revealed 98.88% degradation of monocrotophos with a prominent decrease in the standard peak of monocrotophos (standard rf 0.19- 0.21) within 15 days of incubation as evident by HPTLC chromatograms. Molecular mechanism as studied by FTIR analysis revealed hydrolytic cleavage of vinyl bond with the formation of PO –4 . Degradation of monocrotophos followed first order kinetics with the rate constant (k deg ) of 0.0115 day -1 and half life of 2.53 days. The results of the study conclude that Penicillium aculeatum JQ660374 could be used as an efficient candidate for the detoxification of monocrotophos contaminated sites.