Genetic and Phenotypic Divesity of Petroleum Hydrocarbon-Degrading Bacteria Isolated from Marine Environment

Abstract

Genetic and Phenotypic Diversity of Petroleum Hydrocarbon-Degrading Bacteria Isolated From Marine Environment

Hyo-Sun Lim Major in Plant Microbiology in Agricultural Biotechnology The Graduate School of Seoul National University

Forty hydrocarbon-degrading bacteria were isolated by enrichment culture technique from marine environments and their genetic and phenotypic diversity were investigated. Analysis of 16S rRNA gene sequence indicated that the isolates were related to members of the genera, Alcanivorax, Mariobacter, Mycobacterium, Pseudomonas, Halomonas and Rhodococcus. Nineteen different chromosomal DNA patterns were obtained by polymerase-chain-reaction (PCR) amplification of repetitive extragenic palindromic (REP) sequence from the forty isolates. The isolates were able to utilize hydrocarbon as a sole source of carbon and energy. Among the isolates, strains TA-PH1, YS-P3, and TA-P1 were the most versatile in substrate use, degrading most of the aliphatic and aromatic hydrocarbons tested. Most strains isolated under aromatic hydrocarbon selection also could degrade aliphatic hydrocarbon, but none of the isolates obtained under aliphatic hydrocarbon selection could degrade aromatic hydrocarbon. Six of the nineteen representative isolates had one to three plasmids. Their cured strains could not degrade aromatic hydrocarbon any more, suggesting that the aromatic hydrocarbon degradative genes were on the plasmids in these strains. When analyzed with PCR amplification using primers targeting for previously-reported degradative genes (alkB, ndoB, phnAc, nidA/B and pdoA2) of aliphatic and aromatic hydrocarbons, two aliphatic hydrocarbon-degrading isolates (HS-D1, TA-D9) and three phenanthrene-degrading isolates (YS-P1, YS-P3, YS-P2) did not exhibit any positive PCR DNA bands.