Characterization of crude oil degrading microbial cultures isolated in Qingdao China

9 hydrocarbon-degrading strains were isolated based on their ability to grow with crude oil as the sole carbon source from the water and sediment samples of Qingdao offshore. The isolated microbes, pure and mixed cultures, were demonstrated to degrade petroleum, and petroleum samples that contain higher concentrations of lower molecular hydrocarbons experience greater biodegradation. These cultures are phylogenetically related to previously characterized hydrocarbon degrading microbial cultures, dominated by members of the Pseudomonas cluster, Brevundimonas cluster, Bacillus cluster, and Peptoclostridium cluster. The mixed culture and some individual cultures can form stable emulsions of oil in water and the surfactant activity possessed by these cultures is predominantly associated with the bacterial cells and extracellular polymeric substances.