VOLUME 7 NUMBER 2 (July to December 2014)

by A. Mittsu G. Sarmago and Cynthia T. Hedreyda*

National Institute of Molecular Biology and Biotechnology,
College of Science, University of the Philippines,
Diliman, Quezon City, Philippines 1101

The catechol 1,2-dioxygenase gene (catA) codes for an enzyme that is responsible for the cleavage of aromatic hydrocarbons present in oil-polluted environments. This research focused on the amplification and sequence analysis of the catA gene from Acinetobacter baumannii strain OS1, a strain isolated from oil sludge that exhibited significant bunker oil degradation. PCR using four primers designed to amplify different regions of the strain OS1 catA gene, produced the expected size amplicons of about 641, 643, and 1,122 base pairs. Sequence analysis of partial 641-bp and 643-bp catA gene fragments and the 1,122-bp complete catA gene cloned into pCR^™2.1-TOPO^® vector, revealed the complete sequence of the Acinetobacter baumannii strain OS1 catA gene (GenBank Accession No. KF038386) with 921 nucleotides that are expected to translate into a protein with 306 amino acids. The OS1 catA gene exhibits 99% sequence similarity to the catA gene previously reported in the database for strains AB307 0294, AB0057, and AYE, and 98% similarity with strain SDF of Acinetobacter baumannii. The corresponding amino acid sequence of the catechol 1,2-dioxygenase in strain OS1 is the same for all strains previously studied, except strain SDF with four amino acid differences. The sequence analysis of the complete catA gene from A. baumannii strain OS1 will pave the way for further studies including the expression of the gene in an appropriate non-pathogenic host cell for possible use in addressing petroleum-derived hydrocarbon pollution.