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

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 × 10 7 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 35oC. Key Words: Dechlorination, 16S rDNA, bioremediation, Pseudomonas aeruginosa OK1. African Journal of Biotechnology Vol.3(10) 2004: 508-511