Using Real-time PCR to assess changes in the crude oil degrading microbial community in contaminated seawater mesocosms

The real-time polymerase chain reaction (RT-PCR) was used to follow changes in the proportion of hydrocarbonoclastic bacteria in the marine microbial community in oil polluted mesocosms during bioremediation field trial. Assay for alk-B1 of Alcanivorax borkumensis and alk-BT of Thalassolituus oleivorans were validated and found to be both sensitive and reproducible. Quantification of alk-B1 from A.borkumensis SK2 in mesocosms show that in single bioaugmentation mesocosm (M1) this gene has high quantity in fifth day of sampling but in biostimulating mesocosm (M2) and consortium bioaugmentation mesocosm (M3) the high quantity of this gene was in tenth day of sampling. The comparison between expression of alk-BT and alk-B1 in M3 mesocosm show that alk-B1 copy number was more than alk-BT. The proportion of alk-B1 or alk-BT containing bacteria was positively correlated to the concentration of crude oil in the mesocosms. After the concentration of crude oil in the mesocosms decreased the gene copy number of alkane monooxygenase genes also decreased. © 2014 Elsevier Ltd.