Isolation and characterization of phenol utilizing bacteria from industrial effluent-contaminated soil and kinetic evaluation of their biodegradation potential

Abstract

Microbial degradation of phenol by pure bacterial species is a well-known approach towards alleviation of environmental pollution. In this study, five phenol-degrading bacterial species designated as CUPS-1 to CUPS-5 were isolated from the oil-effluent dumped sites of Haldia Industrial area of West Bengal, India. Detailed morphological, biochemical and molecular characterization identified CUPS-3 as a novel strain- Stenotrophomonas maltophilia (GU358076), while the others could be identified as Pseudomonas (CUPS-2, 5), Delftia (CUPS-1) and Micrococcus (CUPS-4) genera, respectively. Although all of these strains utilized phenol as their sole carbon source supporting growth, three among them, CUPS-2, CUPS-3 and CUPS-5 proved potential phenol degraders and hence used for further biodegradation studies. Degradation experiments were carried out for several initial phenol concentrations of 500 mg/L, 750 mg/L, 1000 mg/L, 1250 mg/L and 1500 mg/L. The novel strain, CUPS-3 could completely degrade 500 mg/L phenol within 48 h, with 0.0937/h substrate degradation rate and 16.34 mg/L/h substrate consumption rate. The strains degraded phenol via meta-cleavage pathway. Prediction of kinetic parameters of the biodegradation was accomplished Haldane model using the experimental data of degradation rate and phenol concentration as function of time.

Keywords:

• Phenol biodegradation
• Stenotrophomonas maltophilia
• degradation pathway
• kinetics
• Haldane model

Acknowledgments

The authors (SPB and PS) are indebted to DST (India) for providing research grant under SERC Scheme. The author SPB would like to thank Amit and Dr. P.K. Maity of University of Calcutta for SEM facility.