Author(s)

S. Farooq, I. Hashmi, M. Arshad & I. A. Qazi

Abstract

A lab scale study was conducted to investigate the degradation of S-Metolachlor (82.1 % W/W) using indigenous soil culture. S-Metolachlor is a pre-emergent acetanilide herbicide for the control of annual grasses and broadleaf weeds. Health advisory level (HAL) of S-Metolachlor by US EPA is 0.525 mg/L in drinking water. The bacterial culture capable of degrading S-Metolachlor was isolated from soil with the help of an enrichment technique. Isolated bacterial cultures were identified as Pseudomonas sp. by using morphological and biochemical characteristics. Molecular identification of Pseudomonas sp. with the help of Polymerase Chain Reaction (PCR) was also conducted. Pure culture of Pseudomonas aeruginosa (ATCC 27853) was used to determine its degradation capacity. By using incubator an orbital shaker bacterial degradation capacity at 10, 20 and 50μg/ml were determined. Gas chromatography and total organic carbon (TOC) were used to determine the concentration of S-Metolachlor at varied time intervals. TOC of S-Metolachlor was found to be 169.6 ppm. Isolated Pseudomonas sp. and standard culture of Pseudomonas aeruginosa (ATCC 27853) showed higher degradation capacity of S-Metolachlor. Keywords: S-Metolachlor, biodegradation, Pseudomonas sp., acetanilide herbicide, polymerase chain reaction, gas chromatography, enrichment technique.

Keywords

S-Metolachlor, biodegradation, Pseudomonas sp., acetanilide herbicide, polymerase chain reaction, gas chromatography, enrichment technique