Degradation of Dimethoate by Cellulolytic Bacteria in Cotton Soils

Abstract

The present experience has been aimed to isolate bacteria specifically cellulolytic bacteria, normally found in cotton soils and determine their role in degradation of the specific pesticide. Two cellulolytic bacterial isolates k1 & k2 identified as Pseudomonas putida and Bacillus pumulus were capable of growing on dimethoate supplemented medium. P.putida exhibited maximum growth of 4.1x 106 cfu/ ml at 0.09 mg/ml while B.pumulus showed significant growth of 2.2 x107 cfu/ml at 0.06mg/ml of dimethoate after 72hrs of incubation at room temperature. Rate of utilization of dimethoate increased progressively with increase in the concentration of yeast extract added to the medium up to 0.56% in P.putida and 0.7% in B.pumulus. The present findings indicate that among the two bacterial isolates, sps of Pseudomonas could degrade 88% of dimethoate while Bacillus sps exhibited high degradation rate of 92% which can be commercialized for bioremediation of dimethoate contaminated sites. Further, the rate of degradation is maximum at 72hrs of incubation.