SCREENING AND CHARACTERIZATION OF NAPHTHALENE DEGRADING BACTERIA

Abstract

Aim: Present investigation was carried out to study the screening and characterization of naphthalene degrading bacteria. Naphthalene is toxic to blood, kidneys, nervous system etc. Thus the aim of the study was to isolate cultures from oil spilled soil samples in Chennai and to study the naphthalene degrading bacteria present in sample. Methods: Samples were collected and isolated. Best grown isolates were selected and were maintained in M9 medium and stored at 4°C. Biochemical and physiological characterization were carried out. Biodegradation study with naphthalene adapted bacterial strains were done at optimized conditions. Results: A total of 8 strains were isolated and two strains P3 and P6 showed rich growth on 200 ppm naphthalene. These two strains were selected as naphthalene degrading bacteria and used for further studies. Discussion: These samples were extracted at 0 to 7 days for calculating the efficiency of both the strains. Strain P6 (Pseudomonas sp) was found to be more efficient to degrade naphthalene than strain P3. Genomic studies were carried out and the genetic relationship between the strains and known members of other species of Pseudomonas genus were estimated by parsimony analysis. Conclusion: Hence it was concluded that Pseudomonas aeruginosa is one of the most common strains found in oil spill region because soil is a rich source of microbes. These microbes have the ability to degrade the pollutants efficiently in the culture. PAH contaminated soil and sediments can be exploited further to study other bacterial strains capable of degrading PAHs and organic contaminants.