• 한국환경과학회지
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• 제18권11호
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• pp.1261-1270
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• 2009

Fifty hydrocarbon-metabolizing microorganisms were isolated from soil samples polluted by the petroleum oils in Gamman-dong, Busan. Among them, strain 2-3A, showing strong emulsification activity, was selected by oil film-collapsing method. This bacterium was identified as Acinetobacter sp. and designated as Acinetobacter sp. 2-3A. The optimum temperature and pH on the growth of Acinetobacter sp. 2-3A were $25^{\circ}C$ and pH 7.0, respectively. The carbon and nitrogen sources for the most effective emulsification activity were 3.0% olive oil and 0.5% peptone, respectively. The 0.15% potassium phosphate was the most effective emulsification activity as a phosphate source. The optimum emulsification activity condition was $20^{\circ}C$, pH 7.0, and 2.0% NaCl. The optimum time for the best production of biosurfactant was 27 hrs. The emulsification stability was maintained at the temperature range from $4^{\circ}C$ to $100^{\circ}C$, pH range from 6.0 to 10.0, and NaCl range from 0% to 10%. For the oil resolvability of the biosurfactant, the residual oils were investigated by gas chromatography. As a result, it was verified that the biosurfactant decreased and decomposed crude oils from $_nC_{10}$ to $_nC_{32}$.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.420-426
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• 1997

Pseudomonas sp. lipase (lipase AK) catalyzed transesterification reaction between fructose and vinyl laurate in anhydrous pyridine. The product of this process was identified as monoester of fructose and vinyl laurate. The synthetic product has been found to be an excellent emulsifier. The synthetic bioemulsifier showed a good emulsification activity and stability in comparison with other commercial emulsifiers, and good emulsification activity on various emulsifying substrates.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.282-295
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• 2005

The processing of dietary lipids can be distinguished in several sequential steps, including their emulsification, hydrolysis and micellization, before they are absorbed by the enterocytes. Emulsification of lipids starts in the stomach and is mediated by physical forces and favoured by the partial lipolysis of the dietary lipids due to the activity of gastric lipase. The process of lipid digestion continues in the duodenum where pancreatic triacylglycerol lipase (PTL) releases 50 to 70% of dietary fatty acids. Bile salts at low concentrations stimulate PTL activity, but higher concentrations inhibit PTL activity. Pancreatic triacylglycerol lipase activity is regulated by colipase, that interacts with bile salts and PTL and can release bile salt mediated PTL inhibition. Without colipase, PTL is unable to hydrolyse fatty acids from dietary triacylglycerols, resulting in fat malabsorption with severe consequences on bioavailability of dietary lipids and fat-soluble vitamins. Furthermore, carboxyl ester lipase, a pancreatic enzyme that is bile salt-stimulated and displays wide substrate reactivities, is involved in lipid digestion. The products of lipolysis are removed from the water-oil interface by incorporation into mixed micelles that are formed spontaneously by the interaction of bile salts. Monoacylglycerols and phospholipids enhance the ability of bile salts to form mixed micelles. Formation of mixed micelles is necessary to move the non-polar lipids across the unstirred water layer adjacent to the mucosal cells, thereby facilitating absorption.

• 한국환경과학회지
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• 제6권5호
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• pp.473-480
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• 1997

Microorganisms producing bioemulslfiler were isolated from the sea water In Pusan coastal area. The isolated strain which had the highest emulsification activity and stability was identified as the genus Achetobacter from the results of morphological. cultural and biochemical tests and named Achetobacter sp. EL-C6 for convenience. The compositions of optimum medium for emulsification of crude oil by Acinetobacter sp. EL-C6 were crude oil 2.0%, NH4NO3 0.2%, $K_2HPO_4$ 0.01%, $MgSO_4$.$7H_2O$ 1.o%, $CaCl_2$.$2H_2O$ 0.1% and NaCl 3.0% at initial pH 7.5 and 3$0^{\circ}C$, respectively. The cultivation for emulsification of crude ell was carried out in 500m1 shaking flask containing 100m1 of the optimum medium at 3$0^{\circ}C$. The highest emulsification was observed after 5 days. The utilization on the various hydrocarbon of the Achetobacter sp. EL-C6 showed that utilization of n-alkane compounds were better than that of aromatic compounds. Among the petroleum compounds, crude ell was best utilized by the Achetobacter sp. EL-C6.

• Applied Biological Chemistry
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• 제50권1호
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• pp.12-17
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• 2007

태백산 토양에서 유화활성과 안정도가 높은 biosurfactant 생산균주 TBM 3101을 분리하여 동정한 결과 B. subtilis로 판명되었다. B. subtilis TBM 3101의 배양액에서 표면장력은 최저 29mN/m까지 감소되었고, 이후 장시간 계속 유지되었다. 또한, tributyrin을 기질로 사용하였을 때 2.68로 가장 큰 유화력을 보였고, 그 외에 soybean oil, crude oil, tetradecane 에서도 비슷한 활성을 보였다. 각종 다른 합성계면활성제의 유화활성 및 안정성을 고려하여 비교 분석한 결과 B. subtilis TBM 3101 생산하는 biosurfactant는 tween류와 span 85와 유사한 유화활성을 나타내었고, tween 80과 triton X-100과 비슷한 유화 안정도를 보여주었다.

• 생명과학회지
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• 제14권5호
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• pp.834-839
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• 2004

원유 분해능이 강력한 해양균주 Klebsiella sp. KCL-1의 표면활성 능력과 유화활성의 향상을 위하여 An et. al.이 보고한 Pseudomouas sp. SW-3균주로부터 cloning된 pET-Lip을 KCL-1에 도입하였다. KCL-1/pET-Lip은 2% glucose, 4% soybean oil, 4% kerosene 각각의 탄소원에 대하여 야생형균주 KCL-1과 비교하여 우수한 표면장력 저하 능력을 가지게 된 것을 알 수 있다. KCL-1/pET-Lip은 4% soybean oil를 유일한 탄소원으로 배지에 첨가한 경우 표면장력이 55 dyne/cm에서 32 dyne/cm로 줄어들었다. 세포의 성장은 2% glucose가 탄소원으로 사용된 경우 성장이 최대로 확인되었다. 0.2% glucose와 2% soybean oil을 복합적으로 첨가한 경우 2% glucose를 탄소원으로 사용한 경우에 비해 균의 생육도는 별 차이를 보이지 않으나 표면 장력에는 뚜렷한 차이를 보였다. 4% soybean oil을 사용한 경우와 비교할 경우 균의 생육도는 월등히 높으며, 표면장력의 저하능은 96시간째에 차이가 2 dyne/cm로 비슷해진다. 따라서 탄소원으로서 glucose는 세포의 성장과 관련이 있고, soybean oil 경우는 표면 장력 저하와 관계가 있는 것으로 예상된다. 또한 유화활성의 경우 사용된 모든 기질에 대하여 유화활성이 증가하는 것을 확인하였다. 특히 대두유를 기질로 사웅한 경우 유화활성이 가장 높았다 대두유를 탄소원으로 사용하여 KCL-1/pET-Lip 을 48, 72, 96시간 배양한 세포 추출물에서 42 kDa의 lipase로 추정되는 단백질이 발현됨을 확인하였다. 결과적으로 lipase를 도입한 KCL-1/pET-Lip의 표면활성 변화 능력이 월등히 향상된 것으로 추정된다.

• 공업화학
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• 제34권3호
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• pp.299-306
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• 2023

본 연구에서는 무환자와 알팔파로부터 추출한 천연계면활성제를 유화제로 사용하여 반응표면분석법 중 중심합성계획모델(CCD-RSM)을 이용한 O/W 유화 제조공정의 최적화를 수행하였다. 공정변수로는 혼합유화제 첨가량, 천연유화제 혼합비율(무환자 사포닌/알팔파 사포닌), 유화시간으로 설정하였고 반응치로는 유화액의 유화안정화지수, 평균입자크기, 항산화능(DPPH 라디칼 소거활성)으로 설정하였다. 기초실험을 통한 계량인자범위는 혼합유화제 첨가량(12~14 wt%), 천연유화제 혼합비율(30~70%), 유화시간(20~30 min)으로 설정하여 CCD-RSM을 이용하여 최적화한 결과, O/W 유화 제조공정의 최적조건으로 혼합유화제 첨가량은 13.2 wt%, 천연유화제 혼합비율은 44.2%, 유화시간은 25.8 min으로 나타났으며, 이 조건에서 예측된 반응치로서 유화액의 유화안정도지수(ESI)는 88.7%, 평균입자크기(MDS)는 815.5 nm, 항산화능은 38.7%으로 계산되었다. 이를 실험을 통해 확인한 결과 유화액의 ESI는 90.6%, MDS는 830.2 nm, 항산화능은 39.6%으로 나타났으며 평균오차율은 2.1%이었다. 따라서 CCD-RSM을 실제 유화 제조에 적용하여 만족스러운 O/W 유화제조 공정조건을 얻을 수 있었다.

• 한국식품영양학회지
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• 제34권6호
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• pp.561-567
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• 2021

Curcumin is not soluble in water. Therefore, curcumin emulsion that can dissolve well in water were prepared using multi-emulsification technology, and the antioxidant activities and physical properties of emulsion were measured. Although curcumin was not dissolved in water, it was confirmed to be well dispersed in water when prepared in an aqueous dispersion curcumin emulsion. After dissolving curcumin using water and ethanol as solvents, respectively, the DPPH and ABTS radical scavenging abilities of the filtrate and the curcumin emulsion were measured. Because it was not dissolved in water, activities were not shown. However, when curcumin was dissolved in ethanol, the activities increased as the concentration of curcumin increased. On the other hand, when the curcumin emulsion was dissolved in water, it was found to have abilities. The curcumin emulsion was nano-homogenized and the size and distribution of the emulsified spheres were measured. It was confirmed to be nano-sized as it appeared as 9.083 nm/100%. In the results of the DPPH radical and ABTS radical scavenging abilities of curcumin nano-emulsion, it was confirmed that there was no change in the antioxidant abilities. In conclusion, water-dispersible curcumin prepared using multi-emulsification technology, and it was confirmed to exhibit antioxidant activity and emulsion stability.

• Journal of Microbiology and Biotechnology
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• 제7권3호
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• pp.209-211
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• 1997

A quantitative method for assaying bioemulsifiers in culture broth was developed and applied to cultivation of Pseudomonas aeruginosa YPJ80. SED(Standard Emulsification Dilution), an indirect measure of bioemulsifier concentration, was proposed. Production of bioemulsifier and rhamnolipid reached their maximum simultaneously. However, the bioemulsifier/rhamnolipid ratio decreased with cultivation time. This indicates the presence of another bioemulsifier other than rhamnolipid. The bioemulsifier seems to be protein-like activator which showed emulsification activity in addition to rhamnolipid.

• Journal of Microbiology and Biotechnology
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• 제6권3호
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• pp.184-188
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• 1996

The Acinetobacter sp. BE-254 isolated from soil sources produced a bioemulsifier in the medium supplemented with n-hexadecane. This bioemulsifier was purified by the procedures of fractionation (ammonium sulfate and chilled acetone), extraction by hexane, and column chromatography on silica gel 60. The results from various color reactions indicated that the bioemulsifier was a glycolipid. The purified emulsifier was very stable at pHs ranging from 4 to 10 and under heat treatment at $100^{\circ}C$ for 30 min. Emulsification activity was also hardly influenced by pH. The critical micelle concentration (CMC) and surface tension at the point ($\gamma_{cmc}$) of the bioemulsifier were approximately 35 mg/l and 30 mN/m, respectively. The bioemulsifier showed a fairly good emulsification activity and stability in comparison with other commercial emulsifiers in the basic formula composed of emulsifier, oil, and water.