• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.325-325
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• 2005

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.227-235
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• 2013

This study was conducted to prove the effect of irradiation on lipases (lipase AK, lipase AH, lipase PS-D, Lipozyme TLIM, Lipozyme RMIM and Novozyme SP435) which were used for interesterification reaction using batch type reactor. Through such interesterification, structured lipid (1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl, POS) was synthesized by lipase treated with irradiation at different doses (0, 3, 7, 14, 29 and 59 kGy) using canola oil, palmitic ethyl ester (PEE) and stearic ethyl ester (StEE). After the reaction, fatty acid composition of triacylglycerol (TAG) in structured lipid was analyzed to compare the lipase activity. The results showed that activity of the irradiated lipase AH, PS-D and Novozyme SP435 with certain dose (3 kGy) were slightly improved. Such change of lipase activity suggested that irradiation might affect on the interesterification properties. Especially, Lipase AK, Lipozyme TLIM and Lipozyme RMIM after at 3 kGy irradiation showed that content of stearic acid ($C_{18:0}$) was increased while palmitic acid ($C_{16:0}$) decreased in the interesterified products.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.562-565
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• 2002

The esterification reaction of previously obtained l,4-sorbitan with acrylic acid using Novozym 435 was carried out in t-butanol as solvent. Immobilized lipase Novozym 435 showed high enzymatic activity at $50^{\circ}C$ in t-butanol and optimum contents of Novozym 435 added in the esterification reaction was 3%(w/v). The maximum conversion rate was 55.8% when initial concentration was 50g/L and conversion rate of this reaction was 63.5% when the molar ratio of l,4-sorbitan to acrylic acid was 1:3.

• KSBB Journal
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• v.19 no.5
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• pp.385-389
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• 2004

In this research, the chemo-enzymatic synthesis of sorbitan methacrylate was investigated to optimize reaction conditions. Firstly, sorbitan was manufactured by sorbitol cyclic reaction in the presence of p-toluenesulfonic acid (p-TSA) as catalyst material. Secondly, sorbitan methacrylate was synthesized by immobilized lipase Novozyme 435 with acyl donors in t-butanol. As a result of enzymatic synthesis of sorbitan methacrylate, the conversion yield reached about $65\%$ in the condition of initial sorbitan conc. 50 g/L, enzyme content $3\%$ (w/v) , molar ratio 1:3, reaction temperature 50^{circ}C and reaction time 42 hrs using methyl methacrylate as acyl donor. Comparing with acyl donors and reaction temperature, the conversion yield reached about 18, 65 and $80\%$ with methacrylic acid, methyl methacrylate and vinyl methacrylate as acyl donor, respectively. And optimum reaction temperature was 60, 50, and 50^{circ}C, respectively

• Journal of Life Science
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• v.25 no.3
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• pp.345-348
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• 2015

An organic solvent stable lipase from solvent-tolerant Pseudomonas sp. BCNU 171 had an optimal pH of 8 and an optimal temperature of 37℃. This crude extracellular lipase from BCNU 171 exhibited increased stability in the presence of various types of solvents at high concentrations (25%, v/v). The lipase stability was found to be highest in the presence of xylene (137%), followed by toluene (131%), octane (130%), and butanol (104%). Overall, BCNU 171 lipase tended to be more stable than immobilized commercial lipase (Novozyme435) in the presence of organic solvents. Furthermore, BCNU 171 lipase maintained about 90% of its enzyme original activity in the presence of NH₄⁺, Na⁺, Ba²⁺, Hg²⁺, Ni²⁺, Cu²⁺, and Ca²⁺ion and significantly increased its enzyme activity in the presence of various emulsifying agents. Thus, the organic solvent stable lipase from Pseudomonas sp. BCNU 171 could be usable as a potential whole cell biocatalyst and for synthetic applications of enzymes for industrial chemical processes in organic solvents without using immobilization.

• KSBB Journal
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• v.27 no.1
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• pp.61-66
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• 2012

In the screening process of organic solvent tolerant bacteria showing good growth in media containing several kinds of organic solvents, one strain was isolated and identified as Bacillus sp. BCNU 5006. The strain was able to tolerate many organic solvents including benzene, toluene, xylene, octane, dodecane, butanol and ethylbenzene. Likewise, it could also utilize these solvents as the sole source of carbon with significant enzyme production. The lipolytic enzyme stability of Bacillus sp. BCNU 5006 was studied in the presence of several kinds of solvents at a 25% (v/v) concentration. The highest enzyme stability was observed in the presence of octane (107%), followed by ethylbenzene (88%), decane (86%), and chloroform (85%). Especially, BCNU 5006 lipase was determined to be more stable than immobilized enzyme (Novozyme 435) in the presence of octane, chloroform and xylene. This organic solvent tolerant Bacillus sp. BCNU 5006 could be expected as a potential bioremediation agent and biocatalyst for biodegradation and provide on organic-solvent-based enzymatic synthetic method in industrial chemical processes.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.177-182
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• 2008

This study was carried out to investigate the reaction of lipase-catalyst transesterification using animal fat recovered from fleshing scrap generated during leather making process. Transesterification reaction between fat and primary or secondary alcohol was carried out under the condition of immobilized enzyme catalyst. The conversion rate was the highest when 1.5 mole of methanol was injected by 4 times. As for lipase, Candida antarctica showed the highest conversion rate of 82.2% among the 4 different lipases. It was found that water contained in the fat causes lower conversion rate. The condition of 1.2wt. % of water in the fat decreased the conversion rate by 40%. It was considered that the resulted reactant, fatty acid ester could be used as raw material for biodiesel with the characteristics of not generating SOx and diminishing smoke.