Abstract

Previously we isolated three native strains, Rhodococcus FRF, IPF and GAF from Tabriz and Tehran refineries soil samples in a search for flavin reductase gene (dszD). In this study, these three flavin reductase genes were isolated and identified by PCR using the nucleotide sequence of dszD gene from Rhodococcus sp. The amplified dszD DNA sequences were purified and cloned into the T-vector pTZ57R/T and then introduced to the E. coli DH5α. Further sequence analysis revealed that the oxidoreductase genes of Rhodococcus FRF, IPF and GAF share high similarity to that of Rhodococcus erythropolis IGTS8. There were differences only in a few number of nucleotide. Also oxidoreductase enzymes in all strains consist of 193 amino acids that differ only in one amino acid which is located at stop condon of Rhodococcus FRF.

Key words: Biodesulfurization, Rhodococcus species, flavin reductase gene (dszD).