POTENTIAL ORGANOPHOSPHATE DEGRADING BACTERIA AND THEIR GENETIC VARIABILITY

Abstract

Profenofos an organophosphate, is a widely used pesticide for agricultural purposes which poses a great threat to entire food chain. Environmental and public health effects of profenofos due to soil, water and environmental contamination require remedial measures. Biodegradation offers the most viable solution for remediation of pesticide contaminated sites. Current study was carried out to isolate the bacterial strains capable of degrading profenofos effectively. Total fourteen pesticide degrading bacteria were isolated from agricultural soil by enrichment culture technique, two potential degrading strains were screened out. Both strains were able to grow at wide pH (6-9) range but showed growth variation at different temperatures (30, 37 and 45◦C). Identification of potential strains were carried out using 16S rRNA analysis which identified the strains as Pseudomonas aeruginosa and Pseudomonas putida. Organophosphate degrading gene was found to be present in both isolates. Profenofos was utilized as second preferred carbon source by both isolates after glucose whereas lactose and methanol exhibited minimum effect on bacterial growth. Degradation studies were undertaken in bench scale reactors and percentage removal of profenofos was determined through Gas Chromatography. At profenofos concentration of 150 mg/L, degradation efficiency of individual isolates and consortium was found to be 69.9, 49.8 and 79.3% respectively within 96 hrs asserting that the efficiency enhanced when consortium of two isolates was inoculated. This study may play a significant role in onsite bioremediation of pesticide industry waste as well as contaminated fields.