Degradation studies of pendimethalin by indigenous soil bacterium Pseudomonas strain PD1 using spectrophotometric scanning and FTIR.

ABSTRACT

In this study pendimethalin degrading indigenous soil bacterium was isolated from rice field (supplemented with pendimethalin) and identified as, Pseudomonas strain PD1 on the basis of 16S rRNA phylogenetic analysis. Biodegradation of pendimethalin by this strain was evaluated by spectrophotometric scanning and FTIR analysis of degraded compounds in minimal salt media. Decrease in concentration of pendimethalin at λmax (430 nm) under spectrophotometric scanning is a measurement of time taken by bacterium strain PD1 to degrade pendimethalin. Degraded products were further analyzed by comparing stretching and bending pattern of chemical groups attached to compounds using FTIR spectroscopy. FTIR profile represented disappearance of nitrate group in degraded product by bacterium strain PD1 in minimal salt medium. Molecular docking of pendimethalin on nitro-reductase was done to suggest first enzyme of pathway used by bacterium strain PD1 to degrade pendimethalin. Analysis on degradation by strain PD1 shows that newly isolated strain PD1 can degrade 77.05% of pendimethalin at 50 mgL-1 concentration in 30 h incubation under room temperature. Thus, the study here shed a light on degradation potential of Pseudomonas.