Evaluation of butachlor biodegradation efficacy of Serratia ureilytica strain AS1: a statistical optimization approach

Butachlor is a chloroacetanilide class of herbicide, commonly administered to control unwanted grasses and broad leaf weeds. Extensive usage of the herbicide has led to the contamination of water bodies and surrounding areas, resulting in an adverse impact on the environment. In the present work, a novel butachlor-catabolizing bacterium Serratia ureilytica strain AS-1 was isolated from an herbicide-contaminated soil. Statistical optimization techniques were used to optimize the butachlor biodegradation. Experimental parameters such as growth temperature, pH of the medium and biomass concentration were found to be significant for butachlor biodegradation. The results obtained indicates that the maximum degradation of 2.08 mg/L/h of butachlor was achieved under the optimal conditions of 32.5 °C of incubation temperature, pH 7.5 and 10% (v/v) inoculum size along with a polynomial mathematical model having R² = 0.9833. The model was corroborated by carrying out experiments at the optimized conditions.