대전일원의 유류오염 지역의 토양으로부터 원유를 단일 탄소원으로 이용하는 총 145균주를 순수분리 하였고, 이중 생물 계면활성제 생성능이 가장 우수한 한 균주를 최종 선별하여 형태 및 생리·생화학적 특성을 조사하고 16S rRNA 염기서열을 분석을 통하여 동정한 결과 Pseudomonas sp.로 확인되어 Pseudomonas sp. Z1이라 명명하였다. 최종 선별된 Pseudomonas sp. Z1은 클로람페니콜과 암피실린 등의 항생제와 리튬, 망간, 바륨 등의 중금속에 대해 강한 내성을 갖고 있었고, 최적 온도와 pH는 각각 30℃와 pH 6.0-7.0으로 확인되었다. Pseudomonas sp. Z1이 생성하는 생물 계면활성제는 배양 10시간 이후부터 배양액의 표면장력이 급격히 감소해, 배양 21시간 후에 최대 28 dyne/㎝까지 감소되었고, 2% 이상의 NaCl을 첨가한 경우 배양액의 생물계면활성제의 활성이 감소하였다.
One hundred forty five bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in the Daejon area. Among these colonies, one bacterial strain was selected for this study based on its low surface tension ability, and this selected bacterial strain was identified as Pseudomonas sp. Z1 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. Z1 showed a high resistance to antibiotics such as chloramphenicol and ampicillin, as well as heavy metals such as lithium, manganese, and barium. It was found that the optimal pH and temperature for biosurfactant production of Pseudomonas sp Z1 were pH 6.0-7.0 and 30℃, respectively. After ten hours of inoculation, the biosurfactant activity of the culture broth decreased rapidly, and had maximum surface tension (28 dyne/㎝) after twenty-one hours incubation. The biosurfactant activity of the culture broth was also decreased up to 2% NaCl concentration.