Bacterial isolate from Arabian gulf coast soils in Saudi Arabia able to degrade Arab crude oil

Petroleum Engineering Department, College of Engineering, King Saud UniversityBy means of the enrichment culture technique, two types of microorganisms were isolated from oil contaminated soil samples gathered from coastal area of Saudi Arabia on the Arabian Gulf. One bacterial isolate has proved its ability to degrade Arab crude oil added to aqueous phases (salts solution, sterile and nonsterile Gulf water) while the other failed to adapt itself in salts solution. The active species was identified as Pseudomonas sp. About 80% of Arab crude oil added to salts solution and nonsterile Gulf water had disappeared within 10 days of incubation by this active isolate. Nonsterile Gulf water yielded higher degradation per cent than sterile Gulf water because of the activation of the indigenous flora and the sufficiency of organic and inorganic nutrients. The bacteria proved optimum degradation per cent at 25° C and 2.5 mg/ml Arab crude oil concentration. Adding nutrients activated the degradation process and phosphorus has proved the best rate among other nutrients. Increasing the inoculum size of bacteria in the presence of sufficient nutrients directly affected the biodegradation per cent of Arab oil added to an aqueous phase