Bacterial survival and n-alkane degradation within Omani crude oil and a mousse

A mixed community of eight bacteria able to degrade crude oil was isolated from contaminated sands around the Gulf of Oman. When the community was introduced into 50% oil-water mousse, it demonstrated long-term survival of one isolate identified as Pseudomonas aeruginosa. In 50 and 75% oil-water mousse, cfuʹs of P. aeruginosa remained at the same levels over 60 days, but a 90% oil-water mixture failed to form a mousse and by day 10 there was no bacterial survival. Respirometry comparing oxygen uptake of P. aeruginosa from a 75% mousse with the same bacteria grown in a nutrient broth gave higher oxidation and greater reduction of n-alkanes for the former, when both were grown on crude oil. The significance of environmental adaptations of bacteria and the reduction of specific alkanes by a single bacterial species are discussed briefly.