Isolation and characterization of insecticide (carbaryl) degrading bacteria from soil.

Abstract

Microbes in the soil can be used to detoxify and breakdown the pesticides in the environment. This study was carried out to isolate and characterize Carbaryl degrading bacteria from soil sample. The sampling was conducted at the tobacco farm at Merang, Terengganu. In order to isolate the bacteria species, serial dilution technique and spread plate onto nutrient agar method were done. As a result, two bacterial isolates have been selected for further study due to its ability to degrade Carbaryl in Minimal Salt Medium containing Carbaryl as carbon and nitrogen sources. The degradation of CarbaryI by both isolates was determined using spectrophotometer (00600nm) and bacterial colony count methods. These two isolated bacteria were named as Isolate 1 (Gram negative-rod species) and Isolate 2 (Gram negative­ diplococci species). From the result, Isolate 1 more rapidly to degrade Carbary! than Isolate 2 within 6 days.Based on biochemical tests and BBL Crystal Identification Kit test, Isolates I was identified as Enterobacter sakazaki. These isolates can be manipulated further to produce potential pesticide-degrader to meet the industrial needs.