활성오니와 하천수로부터 분리한 탄화수소 자화성 미생물 중 배양액의 유화능과 표면장력 저하능이 우수한 균주 1종을 선별하여 자동동정기기를 통해 동정한 결과 Acinetobacter calcoaceticus였다. 본 균주는 수용성 탄소원 및 각종 탄화수소와 식물성 oil 등 다양한 탄소원을 이용할 수 있으며 이 중 ethanol 2％에서 biosurfactant의 생산성이 우수하게 나타났다. 질소원으로서는 urea를 효과적으로 이용하며 어느 정도 질소가 제한된 상태(C/N ratio=6.8)에서 biosurfactant의 생산성이 높게 나타났다. 현재 국내외에서 시판중인 17가지 천연유화제와의 유화력 비교시 biosurfactant의 유화력은 중간 수준인 것으로 나타났다. Biosurfactant를 함유하는 로션 타입의 처방에서는 biosurfactant를 함유하지 않은 처방에 비해 유화안정성이 높게 나타났고 특히 고온안정성은 2배 정도 상승되는 효과를 보였다.

25 hydrocarbon-metabolizing microorganisms were isolated from activated sludges and stream waters. Among them, the bacterium which decreased the surface tension and increased the emulsification power of culture broth mostly was selected. This bacterium was demonstrated to be a strain of Acinetobacter calcoaceticus as a result of automatic identification process by the Vitek System. This strain was able to use the various carbon sources including water-soluble carbon sources, many hydrocarbons and vegetable oils for the cell growth and the biosurfactant production. Among them, ethanol was the most effective carbon source for the biosurfactant production at 2％ concentration. As a nitrogen source, urea was effective and the biosurfactant production was higher at C/N ratio=6.8, a condition of nitrogen limitation to a certain extent. When compared to 17 natural emulsifiers on home and foreign market now, emulsification power of biosurfactant was in middle level. The emulsification stability of biosurfactant-including lotion formulation was higher than that in no biosurfactant formulation and especially increased twofold in 45℃ stability test.