Isolation and characterization of phenol degrading Xanthobacter flavus

Abstract

A soil bacterium isolated from a contaminated site degraded phenol as the sole carbon and energy source was identified as Xanthobacter flavus MTCC 9130. This microbial strain was able to tolerate phenol up to 1100 mg/l concentration. The lag phase increased with the increase in phenol
concentration. The optimum growth temperature was 37°C. The organism could degrade completely within 120 h when initial concentration was less than 600 mg/l. Enzyme assay through cell free extract showed the presence of catechol-1,2-dioxygenase. The specific activity was 0.146 ìmol/min/mg protein. However higher concentrations of phenol in the medium showed a negative effect on the growth of the bacterium. Hence X. flavus can be effectively used for bioremediation of phenol-contaminated sites.