Isolation and characterization of potential pendimethalin degrading bacteria from pesticides polluted soil.

Abstract

The aim of this study was to isolate the bacteria capable of degrading pendimethalin herbicide in mineral salt medium from pesticides polluted soil. The present study was conducted in Aquatic Environment and Health Management Division, ICAR-Central Institute of Fisheries Education, Versova, Mumbai, India in the month of August 2015. A pendimethalin degrading bacterial isolates were isolated from contaminated soil samples through enrichment culture technique. The bacterial isolates were identified and characterized as Bacillus cereus and Asaccharospora irregularis based on biochemical characteristics and 16SrRNA sequence analysis. The growth of the isolates was assessed in mineral salt medium (MSM) containing 1 mg/l of pendimethalin. Both the bacterial isolates can grow up to 500 mg/l of pendimethalin concentration. Pendimethalin was incubated with each of the two isolated bacteria and samplings were done at 0, 7, 14, 21 and 28 days for gas chromatographic analysis in which the loss in the initial pendimethalin concentration was recorded over time. Out of the two bacterial isolates, Bacillus cereus was able to degrade the initial amount to 92 mg/l after an incubation period of 28 days and Asaccharospora irregularis degrades up to 78 mg/l after 28 days incubation. This study showed that degradation of pendimethalin occurred at a higher rate when bacterial isolates were incubated. Thus, the isolates, Bacillus cereus, and Asaccharospora irregularis could be effectively applied to remediate pendimethalin contaminated environment