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Bacterial removal of toxic
phenols from an industrial effluent
J. Lin*, M. Reddy, V.
Moorthi and B. E. Qoma
School of
Biochemistry, Genetics, Microbiology and Plant Pathology,
University of KwaZulu-Natal (Westville), Private Bag X
54001, Durban, Republic of South Africa.
*Corresponding author. E-mail:
linj@ukzn.ac.za. Tel:
+27-31-2607401. Fax: +27-31-2607809.
Accepted
28 April, 2008 |
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Chlorinated phenols, widely used in industries, are of
growing concern owing to their high toxicity,
carcinogenicity and wide distribution in industrial wastes.
In the present study, one Pseudomonas isolate,
identified as Pseudomonas fluorescens, was obtained
using the enrichment process with 2,4,6-trichlorophenol
(2,4,6-TCP) as a sole carbon source. This isolate was found
to be able to degrade various highly chlorinated phenolic
compounds such as pentachlorophenol, 2,4,5-TCP, 2,4,6-TCP as
well as phenol, 2,4-dibromophenol and
2,4-dichlorophenol (2,4-DCP).
The ability of P. fluorescens isolate to remove
phenol from a resin producing industrial effluent was tested
by scanning the spectrum with a UV-VIS spectrophotometer.
The results indicated that this isolate metabolized phenol
in the meta-pathway. The optimal phenol degradation
conditions of P. fluorescens isolate were at pH 7 and
30oC. At the 480 mg/l of phenol concentration,
the highest specific degradation rate of was observed.
Further increases in phenol concentration slowed down the
degradation ability of the isolate. However, P.
fluorescens isolate still has the ability of degrading
phenol at the concentration of 3.2 g/L. The supplementation
of 1% glucose stimulated the growth of P. fluorescens
isolate and enhanced the ability to utilize phenol from the
effluent sample. GC-MS results show that 85.4% of phenol in
the effluent sample was metabolized after 40 days. In
conclusion, P. fluorescens isolated in this study has
the ability of utilizing various chlorophenolic compounds
and demonstrates its potentials of degrading high
concentration of phenol in industrial effluents.
Key
words:
Bioremediation, Pseudomonas fluorescens, industrial
effluent, chlorophenols. |
