• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.497-500
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• 2000

A biosurfactant producing bacteria strain, D2D2 was selected from diesel-contaminated soil, and identified as Pseudomonas aeroginosa. A glycolipid produced by P. aeroginosa D2D2 was purified by ethyl acetate extraction and adsorption chromatography. The biosurfactant was Identified as glycolipid which has two types of biosurfactants as a results of TLC analysis. The purified glycolipid biosurfactant reduced the surface tension of water to 27 dyne/cm. In time course studies of growth and rhamnolipid production in a minimal salts medium containing 1.5% glucose and 1.5% olive oil, a maximum rhamnolipid yield of $11.45gL^{-1}$ was obtained after 5 days.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.371-376
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• 2002

A biosurfactant-producing bacterial strain was selected from diesel-contaminated soil by measuring the oil-film collapsing activity and identified as Pseudomonas aeruginosa D2D2. When glucose and olive oil were used as carbon sources, 11.46 g/1 of biosurfactant was obtained. Based on TLC analysis, the biosurfactant produced from P. aeruginosa D2D2 was identified as a glycolipid, consisting of two types of biosurfactants (Type I and Type II). The purified glycolipid reduced the surface tension of the culture from 72 dyne/cm to 27 dyne/cm. The hydrophilic and hydrophobic moiety of the biosurfactant were rhamnose and ${\beta}$-hydroxydecanoic acid, as determined by FAB-MS and NMR analyses, respectively.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.41-45
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• 1993

Rescently we are interested in the biosurfactant. Biosurfactant have a low toxcity and easily biodegradable compound. Pseudomonas sp. 13 was isolated from soil. This microorganism produced biosurfactant that consists of glycolipid R-1 and R-2. A time course study of fermentation indicated that the appearance of glycolipid in the fermentation broth the commencement of the stationary phase with the respect to biomass. The effect of variation of the media components such as amount of glucose, nitrogen, phosphate and metal ions has been investigated. The following values found to be optimum for biosurfactant production (glucose, $20g/{\ell}$; carbon to nitrogen ratio, 40; carbon to phosphate, 18; $FeSO_4{\cdot}7H_2O\;20mg/{\ell}$).

• Journal of Microbiology and Biotechnology
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• v.23 no.3
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• pp.390-396
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• 2013

Biosurfactants have versatile properties and potential industrial applications. A new producer, B. subtilis TU2, was isolated from the underground oil-extraction wastewater of Shengli Oilfield, China. Preliminary flask culture showed that the titer of biosurfactant obtained from the broth of TU2 was ~1.5 g/l at 48 h (718 mg/l after purification), with a reduced surface tension of 32.5 mN/m. The critical micelle concentration was measured as 50 mg/l and the surface tension maintained stability in solution with 50 g/l NaCl and 16 g/l $CaCl_2$ after 5 days of incubation at $70^{\circ}C$. FT-IR spectra exhibited the structure information of both glycolipid and lipopeptide. MALDI-TOF-MS analyses confirmed that the biosurfactant produced by B. subtilis TU2 was a blend of glycolipid and lipopeptide, including rhamnolipid, surfactin, and fengycin. The blended biosurfactant showed 86% of oil-washing efficiency and fine emulsification activity on crude oil, suggesting its potential application in enhanced oil recovery.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.229-235
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• 1995

The surface tension-decreasing biosurfactant was purified from Rhodotorula muciloginosa G-1. The purification procedure was the solvent extraction of culture broth. To ensure complete extraction, the sample was extracted twice with equal volume of ethylacetate. The crude solution was washed with n-hexane to remove unconsumed soybean oil. The crude sample of biosurfactant was applied to Silica gel column chromatography equilibrated with chloroform, and eluted with chloroform : methanol gradient. Serveral solvent system was used to developed the thin layer chromatography (TLC). The purified biosurfactant sample gave one spot (Rf 0.78). It was estimated that biosurfactant was glycolipid about having M.W.1,500 with standard of polyethyleneglycol by Sephadex LH-20 column chromatography.

• Journal of Life Science
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• v.22 no.2
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• pp.239-244
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• 2012

The purpose of this paper is to analyze the characteristics and chemical components of biosurfactant produced by Pseudomonas sp. G314. Pseudomonas sp. G314 was isolated from soil samples which were contaminated with oil in Daejon area. As such, it produced quality biosurfactant [23]. One type of biosurfactant was kept in a refrigerator, whereas another type of biosurfactant was kept in room temperature. The surface tension activities were then compared. As a result, the biosurfactant from Pseudomonas sp. G314 that was kept at room temperature was stable for 10 days, showing 26.2 dyne/cm of surface tension activity. This result was found to be similar to that of the refrigerator storage. The surface tension of batch culture was 25 dyne/cm, but the culture in the 5 l fermentor was 27 dyne/cm. Therefore, it can be suggested that the large-scale culture is feasible via the fermentor. Biosurfactant from Pseudomonas sp. G314 was estimated to be a kind of glycolipid because it dissolved in acetone and methanol much better than in benzene and toluene [23]. A spot was detected through the elution of silica gel column and the spread of TLC, and the Rf value was 0.58. This spot has a positive reaction with Bail's reagent and rhodamine 6G. Hence, we can conclude that biosurfactant from Pseudomons sp. G314 was a glycolipid containing carbohydrate and lipid.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.32-38
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• 1999

A biosurfactant produced by Tsukamurella sp. 26A was purified by procedures including acid precipitation, ethylacetate extraction, and adsorption chromatography. The purified biosurfactant reduced the surface tension of water from 72 mN/m to 30 mN/m at a concentration of 250 mg/l, whereas the minimum interfacial tension against n-hexadecane was lowered to 1.5 mN/m at a concentration of 40 mg/i. The compound stabilized oil-in-water emulsions with a variety of commercial oils and had strong emulsification and stabilization activities when compared to those of commercial emulsifiers and stabilizers. Surface tension was stable over a broad range of pH (2-12) and temperature ($100^{\circ}C$, 3h). The biosurfactant was identified as glycolipid having a hydrophilic moiety of trehalose.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.645-649
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• 1998

A glycolipid type of biosurfactants was obtained from a strain which had been isolated from soil. The cell was identified as Pseudomonas aeruginosa from taxonomic characteristics and was designated as YPJ80. Thin layer chromatography and deoxyhexose detection tests were done to verify the type of biosurfactant. Critical micelle concentration (CMC) of the surfactant was observed to be 50 ppm and the minimum surface tension was 30.1 mN/m. As an emulsifier, YPJ80 biosurfactant was superior to emulsan in the emulsification of crude Arabian light oil.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1598-1609
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• 2013

Organochlorine pesticide residues continue to remain as a major environmental threat worldwide. Lindane is an organochlorine pesticide widely used as an acaricide in medicine and agriculture. In the present study, a new lindane-degrading yeast strain, Pseudozyma VITJzN01, was identified as a copious producer of glycolipid biosurfactant. The glycolipid structure and type were elucidated by FTIR, NMR spectroscopy, and GC-MS analysis. The surface activity and stability of the glycolipid was analyzed. The glycolipids, characterized as mannosylerythritol lipids (MELs), exhibited excellent surface active properties and the surface tension of water was reduced to 29 mN/m. The glycolipid was stable over a wide range of pH, temperature, and salinity, showing a very low CMC of 25 mg/l. Bio-microemulsion of olive oil-in-water (O/W) was prepared using the purified biosurfactant without addition of any synthetic cosurfactants, for lindane solubilization and enhanced degradation assay in liquid and soil slurry. The O/W bio-microemulsions enhanced the solubility of lindane up to 40-folds. Degradation of lindane (700 mg/l) by VITJzN01 in liquid medium amended with bio-microemulsions was found to be enhanced by 36% in 2 days, compared with degradation in 12 days in the absence of bio-microemulsions. Lindane-spiked soil slurry incubated with bio-microemulsions also showed 20-40% enhanced degradation compared with the treatment with glycolipids or yeast alone. This is the first report on lindane degradation by Pseudozyma sp., and application of bio-microemulsions for enhanced lindane degradation. MEL-stabilized bio-microemulsions can serve as a potential tool for enhanced remediation of diverse lindane-contaminated environments.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.26-40
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• 1993

Many different types of synthetic surfactant are being used, but it is important to develop for a broad range of purposes in a large variety of different application. Biosurfactant are important because the present a much broader range of surfactant types and properties than the available synthetic surfactant Futhermore, they are easily biodegradable and low toxicity, which reduce the potential of pollution. This article discusses the structure and properties of the glycolipid biosurfactants, their production and isolation from fermentation broths and their potential applications.