Pseudomonas aeruginosa EMS1, isolated from activated sludge, was able to grow an produce a biosurfactant on 4.5 % soybean oil, used as the source of energy and carbon. Pseudomonas aeruginosa EMS1 was cultivated at 3$0^{circ}C$ in a reciprocal shaking incubator, and the highest biosurfactant production was observed after 3 days. Furthermore, Pseudomonas aeruginosa EMS1 was also able to use whey as a co-substrate for biosurfactant production and growth