Bioaugmentation of Pseudomonas aeruginosa in Microbial Degradation of P-Nitro Phenol

Abstract

p-Nitrophenol (PNP) occurs as contaminants of industrial effluents and it is the most important environmental pollutant and causes significant health and environmental risks, because it is toxic to many living organisms. Nevertheless, the information regarding PNP degradation pathways and their enzymes remain limited. P. aeruginosa MTCC 7926 was obtained from MTCC Chandigarh, India and cultured in the minimal medium in the presence of PNP. PNP degradation efficiency was compared under different pH and temperature ranges. The degraded product was isolated and analyzed with different chromatographic and spectroscopic techniques. P. aeruginosa 7926 shows good growth and PNP degradation at 37°C in neutral pH. Acidic and alkali pH retarded the growth of P. aeruginosa as well as the PNP degradation. On the basis of specialized techniques, hydroquinone was identified as major degraded product. The pathway was identified for the biodegradation of PNP. It involved initial removal of the nitrate group and formation of hydroquinone as one of the intermediates. Our results suggested that P. aeruginosa 7926 strain would be a suitable aspirant for bioremediation of nitro-aromatic compounds contaminated sites in the environment.