African Journal of Biotechnology Vol. 3 (10), pp. 508-511, October 2004           
ISSN 1684–5315 © 2004 Academic Journals

Full Length Research Paper

Dechlorination of 1,2– dichloroethane by Pseudomonas aeruginosa OK1 isolated from a waste dumpsite in Nigeria

A. I. Okoh¹*, A. O. Olaniran^1,2 and P. Golyshin³

¹Department of Microbiology,Obafemi Awolowo University, Ile - Ife, Nigeria.

²Department of Microbiology, University of Durban-Westville, Durban,South Africa.

³Molecular microbial ecology lab, German Research Center for Biotechnology, Braunschweig, Germany.

*Corresponding author. E-Mail: aokoh98@yahoo.com.

Accepted  9 September 2004

As part of our attempt at isolating and stocking some indigenous microbial species, we isolated a bacterium from a waste dumpsite with appreciable dechlorination activity. 16S rDNA profiling revealed the isolate to be a strain of Pseudomonas aeruginosa and the sequence has been deposited in the NCBI nucleotide sequence database (accession number AJ550306). The bacterium utilized 0.1% (v/v) 1, 2 – dichloroethane (1, 2 – DCE) as sole source of carbon and attained peak cell density of 6.0 × 10⁷ cfu/ml in 48 h. It also has a proportionate increase in chloride release during this period resulting in the release of 80% free Cl^-. The bacterium also had dehalogenase activities against other chlorinated organics such as monochloroacetic acid, trichloroacetic acid, dichloromethane, trichloromethane and tetrachloromethane at pH 7.5 and 9.0. Optimum temperature for dehalogenase activity against 1, 2 – DCE was 35^oC.

Key words: Dechlorination, 16S rDNA, bioremediation, Pseudomonas aeruginosa OK1.