• Korean Journal of Microbiology
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• v.33 no.3
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• pp.187-192
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• 1997

The strain producing biosurfactant was isolated from soil. The isolated strain was identified as the genus Tsukamurella through its morphological, cultural, physiological, menaquinone type, fatty acid composition characteristics. The highest biosurfactant production by Tsukamurella sp. 26A was observed after 4 days cultivation in the culture medium containing n-hexadecane 7%, $NaNO_{3}$ 0.2%, $K_2HPO_4$ 0.001%, $MgSO_{4}$ center dot $7H_{2}O$ 0.02%, $CaCl_2$ center dot $2H_{2}O$ 0.02%, yeast extract 0.02%(pH 6.8-7.0, 30^{\circ}C.$ The surface and interfacial tension of an aqueous solution reached 30 mNim and 1.5 mNim, respectively. The biosurfactant stabilized oil-in-water emulsion with a variety of hydrocarbons, edible oils and petroleum oils.

• KSBB Journal
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• v.13 no.2
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• pp.209-213
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• 1998

The characteristics of de-emulsification of pertroleum emulsion by Nocardia amarae were investigated. Insoluble medium containing n-hexadecane was more effective than soluble medium in de-emulsification of emulsion containing diesel and bunker C as the organic phase. Emulsion made by the addition of xanthan or bioemulsifier was de-emulsified by N. amarae, and longer culture age was effective. In low viscosity range, organic phase with longer carbon chain was more effective. The contact, angle between bacterial film and water droplet in air increased from 16 degree for 4 day culture age to 26 degree for 15 day. The contact angle between bacterial film and water droplet in kerosene, n-heyxane or n-hexadecane also increased to greater than 100 degree after 3 day culture age. The hydrophobicity of bactgerial film increased according to the culture age.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.5
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• pp.412-418
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• 2010

Steam reforming of n-hexadecane, a major component of diesel over Ni-based hydrotalcite-like catalyst was carried out at $900^{\circ}C$ at atmospheric pressure with space velocity of $10,000h^{-1}$ and feed molar ratio of steam/carbon=3.0. Ni-based hydrotalcite catalyst was prepared by a solid phase crystallization (spc) method and characterized by $N_2$-physisorption, CO chemisorption, TPR., XRD, and TEM techniques. It was found that spc Ni/MgAl catalyst showed higher catalytic stability and inhibition of carbon formation than Ni/$\gamma-Al_2O_3$ catalyst under the tested conditions. The results suggest that the modified spc-Ni/MgAl catalyst after optimization may be applied for the SR reaction of diesel.

• KSBB Journal
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• v.15 no.1
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• pp.27-34
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• 2000

A marine bacterium having a high oil-degrading activity was isolated form the oil-polluted southern sea of Korea, and was identified as Pseudomonas aeruginosa and was named Pseudomonas aeruginosa BYK-2. The optimal tmeperatur, culture time, pH and NaCl concentration for biosurfactant production and cell growth showed $25^{\circ}C$, 48h, 7.0 and 0%(w/v), respectively. After cultivation at $25^{\circ}C$, 180 rpm in 250 mL erlenmeyer flask for 7days, 1%(w/v) arabian light crude oil and bunker C oil which are considered to be hardly degradable compounds were degraded 92.1%(w/w) and 76%(w/w) respectively. And then, cell adherence was measured on various carbon sources. The cell adherence indicated over 80% on hydrocarbons(arabian light crude oil, kuwait curde oil, bunker C oil, n-paraffine, n-hexadecane, n-tetradecane) as carbon sources. Lecithin among fatty acids(oleic acid, olive oil, lecithin) showed highest cell adherence of 91.5%. The cell adherence of sugars(arabinose, trehalose, dextrose, galactose, lactose, fructose, maltose, sorbitol, sucrose) observed to be less than 70% except for arabinose, galactose, sorbitol and sucrose.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.525-529
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• 1990

Plant cell cultures of Lithospermum erythrorhizon were performed in stirred tank and packed-bed reactors with in situ extraction by n-hexadecane. The specific shikonin production and volumetric shikonin productivity of stirred tank reactor reached 1.5 mg shikoninlg cell and 400$\mu g$ shikonin/(L.day), respectively. In packed-bed reactor with calcium alginate-immobilized cells specific shikonin production and volumetric productivity reached 2.0 mg shikoninlg cell and 2857$\mu g$ shikonin/(L.day), which were 1.3 and 7.1 times higher than those of stirred tank reactor, respectively. The higher shikonin production and productivity of packed-bed reactor seemed to be due to high cell loading capacity of calcium alginate immobilized cells in packed-bed reactor and improved cell-cell contact.

• Clean Technology
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• v.6 no.1
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• pp.51-60
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• 2000

The soil remediation by non-ionic surfactant solutions ($C_{12}H_{25}O(CH_2CH_2O)_5H$ and Triton X-100) was studied. Depending on the amounts and use of co-surfactants, MPT(phase inversion temperature), dynamic interfacial tension, and the detergency efficiency of the surfactant solutions in soil were investigated. The oils used were kerosene, n-hexadecane, and paraffin oil. With respect to a higher detergency efficiency, a lower interfacial tension and the MPT was very important. The $C_{12}H_{25}O(CH_2CH_2O)_5H$ was better than Triton X-100 on the oil removal from the soil and the effect of oil kinds was kerosene>paraffin $oil{\geq}n-hexadecane$. The co-surfactant, n-dodecanol, reduced the MPT compared to no addition of this, whereas it did not enhance the detergent efficiency.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.71-75
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• 1990

The isolates biodigrading crude oil were examined to characterize thier properties. Isolates which were identified as Acinetobacter lwoffii G1, Klebsiella pneumoniae L25, Pseudomonas maltophilia N246, Xanthomonas campestris M12, and Xanthomonas sp. M28. The optimum concentration of crude oil was 0.15% for the bacterial growth. X. campestris M12, Xanthomonas sp. M28, and K. penumoniae L25 showed the maximal growth at the concentration of 3.5% sodium chloride, indicating that they were derived from sea water. Among the isolates, X. campestris M12, Xanthomonas sp. M28 specially utilized hexadecane and octane, and P. maltophilia N246 utilized octane with optimum concentration of 0.2-0.3% as sole carbon source. The utilization of components of saturate fraction by K. pneumoniae L25 was examined by gas-liquid chromatography. The short-chain saturates are used before the long chain ones although they almost disappear within 8 days of incubation at $30^{\circ}C$.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.274-284
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• 1994

Phase Inversion Temperature (PIT) measurements showed that the addition of polar components such as oleyl alcohol and oleic acid to the system comprising n-dodecylpentaoxyethylene monoether ($C_{12}E_5$), nonpolar oil (n-hexadecane) and water produced large reductions in the PIT. The PIT was lowered as the additive-to-surfactant ratio in the surfactant films in the microemulsion phase was increased. Another dramatic effect of additive was the manner in which it affects the volume of the microemulsion phase at the PIT of the oil and water solubilization characteristics. Microemulsion phase volume was increased rapidly with decreasing PIT, i.e., with increasing amounts of additive in the system. Also with a decrease in PIT, the solubilization parameters of both oil and water in the microemulsion phase were strikingly increased. Even though soil removal data were not available for the conditions where our results obtained, PIT measurement seems a useful starting point for estimating conditions when middle-phase microemulsion formation and its associated high solubilization of oil can be expected.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.452-454
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• 2002

A biosurfactant-producing microorganism, .Pseudomouos sp. EL-G527 was isolated from activated sludge by enrichment culture when grown on mineral salt medium containing n-hexadecane as a carbon source. The biosurfactant from .Pseudomonar sp. EL-G527 exhibited lesser toxicity to bacterial population than synthetic surfactants and in the biodegradation test, biosurfactant was rapidly degraded and lost its activity as surface active material after 1 day incubation. In this study, the biosurfactant from Pseudomonas sp. EL-G527 was effective surface-active compound, more biodegradable and less toxic to microbial ecosystem than various synthetic surfactants.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.144-144
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• 2013