Isolation and Characterization of Dimethoate Degrading Phytopathogen Fungus from Soil

Lots of dimethoate are applied annually in world with the remainder released to environment has brought terrible contamination. Microorganisms play an important role in the biodegradation of pesticide residues in nature. Two fungal strains with dimethoate degradation capability were isolated and named as F1 and F2 after gradual adaptation and enrichment from soil. The further tests were carried out to confirm the biodegradation activity of fungal strains on dimethoate by HPLC. Results showed that strain Fl exhibited more than five times biodegrading activity as high as strain F2 in 100 mg/L dimethoate and nineteen times in 200 mg/L dimethoate and more tolerant in 400 mg/L dimethoate. The strain Fl was capable of degrade 100 mg/L dimethoate completely in 7 days without any other carbon source supplements, but the degradation capability was weaken with the decrease of complexity of carbon source supplements. It seems that strain Fl held highest capability of dimethoate degradation in the condition of hunger. This strain was characterized and identified as Fusarium sp. by ITS sequence analysis. Fusarium is a well-known and widely distributed soil-borne phytopathogen fungus. As well as its damage to agricultural production, Fusarium also hold potential application in environment protection, so we should exploit it reasonable.