Degradation of isoprothiolane by a defined microbial consortium using response surface methodology

A defined microbial consortium was developed for the degradation of isoprothiolane. Isoprothiolane-biodegradation parameters were optimized using Response Surface Methodology (RSM). Three variables chosen for the study were inoculum concentration (50-1500 microg protein ml(-1)), temperature (25-35 degrees C) and pH (4-8) each at levels -1.682, -1, 0, 1 and 1.682. Incubation time of 72 hr was kept constant. Degradation of different concentrations of isoprothiolane was studied. The optimized conditions obtained were, inoculum concentration of 50 microg protein ml(-1) at 30 degrees C and pH between 4-8. The maximum predicted percentage degradation of 100, 100, 100, 100 and 95.5 was obtained respectively for 5, 10, 20, 30 and 50 ppm of initial isoprothiolane concentrations at different pH levels 7.7, 6.8, 6.2, 4.7 and 4.6. Validation of the model indicated that experimental values were found to be in agreement with the predicted one.