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Isolation and
characterization of phenol degrading Xanthobacter
flavus
Adimulam Nagamani1*,
Rupadevi Soligalla1 and Madan Lowry2
1Department
of Biotechnology, Jaipur Engineering College and Research
Centre, Jaipur, Rajasthan, India.
2Department
of Zoology, University of Rajasthan, Jaipur, Rajasthan,
India.
*Corresponding author. E-mail:
nagamani.adimulam@gmail.com.
Abbreviations: MSM,
mineral salts medium; IMTECH, Institute of Microbial
Technology; MTCC, Microbial Type Culture collection;
PAH’s, Polyaromatic hydrocarbons, HAC’s
haloaromatic compounds.
Accepted
10 April, 2008 |
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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
µmol/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.
Key
words:
Bioremediation, catechol-1, 2-dioxygenase, ortho-pathway,
phenol, Xanthobacter flavus. |
