Purification and Characterizationn of Biosurfactant from Marine Pseudomonas sp. CHCS-2

해양으로부터 분리한 Pseudomonas sp. CHCS-2가 생산하는 Biosurfactant의 정제 및 특성에 관한 연구

A marine microorganism producing biosurfactant was isolated from the oil polluted coast of Chung-Mu in Korea, and was identified as Pseudomonas sp.. It produced the biosurfactanl and its optimum culture conditions for pH and salt concentration were 8.0 and 3.0%, respectively. The productivity of biosurfactant from this strain was affected by the nitrogen source used. For the oil resolvability of the biosurfactant, the residual oil in the culture broth with 2% Kuwait crude oil at each time of 48, 96, and 132hr was investigated by gas chromatography. As result of this experiment, it was verified that the biosurfactant acted on C10-C14, of Kuwait crude oil and so the oil was decomposed. The biosurfactant isolated from the supernatant was purified by adsorption to Amberliter XAD-7 and followed by gel chromatography (Sephadex G-100) and HPLC. The purified biosurfactant showed a high value of emulsifying activity at $40^{\circ}C$ and the emulsifying stability was maintained at the temperature range of $30^{\circ}C$∼$60^{\circ}C$. The purified biosurfactant reduced the interfacial tension of Kuwait crude oil remarkably and showed improved dispersing ability compared to those of commercial surfactants such as Tween 80, Tween 60 and SDS.

해양의 유류유출이 잦은 지역으로부터 crude oil 분해능이 뛰어난 미생물을 분리하여 통정한 결과 Pseudomoans 속으로 판명되였으며, 이를 Pseud$\sigma$ moans sp. CHCS-2로 명 명하였다. 이 균주가 배양 중에 생산하는 biosurf actant의 생생 최적 pH 및 NaCI 농도는 각각 8.0 및 3.0% 였으며, 질소원인 peptone에 영향을 받았다. 2% Kuwait crude oil이 첨가된 배양액을 48, 96, 132시간별로 gas chroma­t tography를 이용, 잔류 oil을 분석한 결과 Kuwait crude oil의 C10-CI4부위에 biosurf actant가 작용하여 분해하였으며, 배양 상층액으로부터 Amberlite XAD-7을 이용한 흡착 chromatography와 Sepha­d dex G-100을 이용한 gel chromatography, 그리고 HPLC를 이용하여 biosurf actant를 분리. 정제한 결과 유화력이 뛰어난 단일 peak를 얻었다. Bio-sur­f f actant 유화력은 $40^{\circ}C$에서 가장 좋았으며, 안정성 은 $30^{\circ}C$에서 $60^{\circ}C$까지의 넓은 온도 범위에서 유지 되었다. 또한, 정제된 biosurf actant를 이용하여 계 연장력에 미치는 영향을 검토한 결과, 상엽적으로 널리 판매되고 있는 Tween 80, Tween 60 그리고 SDS보다 표연장력 저하능력이 뛰어난 것으로 밝혀졌다.