Response Surface Methodology for the Optimization of Chlorpyrifos-Degrading Conditions by Pseudomonas stutzeri ZH-1

Abstract

The removal of pesticides in the environment mainly depends on natural degradation, especially on microbial degradation. Biodegradation has many advantages, such as complete degradation, no secondary pollution, quick effect and wide spectrum. Based on the single-factor experiments and Box-Benhnken design, the effect of four factors on the degradation of chlorpyrifos by P. stutzeri ZH-1 was investigated. The four factors, including temperature (℃), oscillator speed (rpm), inoculum concentration (%) and pH, and their interactions on the degradation of chlorpyrifos were studied through the use of response surface analysis. The optimal conditions of chlorpyrifos-degrading were as follows: Temperature 36.7？C, oscillator speed 130.00 rpm, inoculum concentration 7%, pH 7. Under these conditions, the degradation rate of chlorpyrifos was 96.48%. Moreover, P. stutzeri ZH-1 could be used efficiently for remediation of contaminated soils.