catA Gene in a Potential Corynebacterium Strain is Responsible for its Efficiency in Phenol Bioremoval

Abstract

Out of 10 bacterial strains isolated out of wastewater of a pharmaceutical industry the most efficient bacterium, which could tolerate 5,000 mgl⁻¹ of phenol in the minimal medium, was identified to be Corynebacterium sp.DST1 through 16S rDNA analysis. This strain could remove 99.4% of phenol from the minimal medium containing 4,000 mgl⁻¹ of phenol. The ortho catalytic pathway using the enzyme catechol 1, 2- dioxygenase was found to be the major pathway for phenol degradation in the bacterium. The gene for catechol 1, 2-dioxygenase (catA) could also be amplified using degenerate primers. Corynebacterium sp.DST1 cells were attached to sawdust and removal of phenol from industrial effluents was evaluated. About 92.7% of phenol could be removed from the effluent of a heavy electrical industry. The results of this study not only suggest the potentiality of the strain to remove phenol efficiently from crude industrial effluents but also display a cheap method of bioremediation using sawdust.

Key Words:

• 16S rDNA
• catA
• corynebacterium
• degenerate primers
• phenol
• PCR
• sawdust

Acknowledgments

The authors wish to acknowledge the Late Mrs. Rekha Sharma from the Institute Instrumentation Centre, IIT Roorkee for helping us to carry out SEM studies. The authors also thank the Department of Science and Technology, Government of India, New Delhi for funding this research.