Bioremediation Capabilities of Oil-degrading Bacterial Consortia Isolated from Oil-contaminated Sites at the Gulf of Aqaba (Jordan)

Crude petroleum-oil is a complex mixture of hydrophobic components like n-alkanes, aromatics, resins and asphaltenes. Microorganisms are known to attack and degrade a specific component as compared with other components of oil. This study aimed at investigating the biodegradation potential of 20 bacterial consortia that were previously isolated from 20 different contaminated sites at the Aqaba region and to screen their potential to biodegrade different types of hydrocarbons and clean up oil spills in different contaminated sites in Aqaba (Jordan) in situ and ex situ. In these contaminated soil and seawater sites, the concentrations of Total Petroleum Hydrocarbon (TPH) ranged between 45000-65000 ppm in soil and 25000-35000 ppm in seawater. Twenty different bacterial consortia from soil and seawater samples of a petroleum contaminated sites were constructed and screened for their ability to degrade crude petroleum oil. In general, bacterial consortia derived from contaminated soil and seawater sites showed maximum percentage of degradation 85 and 70%, respectively, of crude oil after 11th week of incubation. However, this study demonstrated that microbial consortia or microbial population of crude oil biodegraders could be maintained for extended periods while at and still be effective in degrading crude oil or other mixtures of toxic organics even high concentrations.