Isolation of oil degrading bacteria from oil contaminated soils, their molecular characterisation and determination of their oil degradation potentials

This study was conducted to isolate petroleum degrading bacteria from crude oil contaminated soils, characterise them at the molecular level, and determine their petroleum degradation potential. Soil samples were obtained from Azerbaijan, contaminated with crude oil, and then studied. Bacteria isolated using laboratory procedures appropriate for bacterial isolation were examined using DNA isolation and PCR techniques for molecular identification following morphological and biochemical analyses. Furthermore, the effects of the bacteria on petroleum degradation were evaluated using spectrophotometric measurements. The findings reveal the potential of these bacteria in ecologically sustainable bioremediation approaches. As a result of the studies, pure cultures of five bacteria with bioremediation potential were obtained. Characterisation revealed that the microorganisms capable of degrading crude oil belonged to the strains Pseudomonas neustonica, Bacillus licheniformis, Corynebacterium stations, Sphingobacterium soli, and Lysinibacillus fusoformis.GC-MS analyses were performed to observe the petroleum degradation effect of the obtained bacterial strains. As a result of the analyses, a total of 10 different compounds were obtained in the samples. These compounds include aliphatic alcohols, ketones, and short-chain carboxylic acids. The obtained Kovats index values range from 810 to 1813. These results were found to be largely consistent with reference values in the literature. In particular, it was understood that short-chain organic acids in the C2–C5 range indicate microbial metabolism. Based on a similarity ratio of 99.79%, the Pseudomonas neustınica bacterium was found to play a more dominant role in petroleum biodegradation.