Quantitative PCR analysis of diesel degrading genes of Acinetobacter calcoaceticus isolates

Abstract

Acinetobacter strains LT 1 and V 2 were grown in Bushnell-Haas medium with 1% diesel and their expression levels of eight diesel-degrading genes were evaluated by quantitative polymerase chain reaction (PCR). LT 1 and V 2 isolates achieved 86.2 and 89.7% degradation respectively, after 60 days with no significant differences in expression, in comparison with 16S rRNA, rubB and lipB. LT 1 showed higher expression levels of rubA, alkM, alkR and xcpR genes during the initial stages of incubation corresponding to higher level of degradation rate. Amplification of alkM, alkR and xcpR genes of V 2 indicated more than one enzyme system involved in the process. Low lipB and lipA expression in LT 1 and no lipA expression in V 2 suggested the absence of lipases in degradation; however, estB gene was predominantly expressed in V 2 . Thus, isolates LT 1 and V 2 possessed comparable efficiency in degrading diesel; however, more complex systems have been employed by V 2 i n degradation process.