• 한국의류학회지
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• 제36권6호
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• pp.653-662
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• 2012

This study measured the effect of general pre-treatment on PLA fabrics to confirm the benefits of enzymatic processing on PLA fabrics in the textile industry as well as evaluated the hydrolytic activities of three lipases. The effects of lipase hydrolysis were analyzed through moisture regain, dyeing ability, tensile strength, and surface morphology. As a result, PLA fibers were easily damaged by a low concentration of sodium hydroxide and a low treatment temperature. The optimal treatment conditions of Lipase from Candida cylindracea were pH 8.0, $40^{\circ}C$, and 1,000 U. The optimal treatment conditions for Lipase from Candida rugosa were pH 7.2, $37^{\circ}C$, and 1,000 U. The optimal treatment conditions for Lipase from Porcine pancreas were pH 8.0, $37^{\circ}C$, and 2,000 U. The moisture regain and dyeing ability of PLA fabrics increased and the tensile strength of PLA fabrics decreased. The results of surface morphology revealed that there were some cracks due to hydrolysis on the surface of the fiber.

• KSBB Journal
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• 제18권1호
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• pp.1-7
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• 2003

항진균제로 잘 알려진 아졸계 화합물인 이트라코나졸 전구체에 대한 광학선택성 lipase 생산균주 탐색을 수행하였다. 본 라세믹 기질을 선택적으로 가수분해하는 lipase 생산균주 인 Acinetobacter sp. SY-01 를 분리하였고, 효소 가수분해반응을 수행한 결과 본 라세믹 기질은 전환율이 74.8%에 도달하였을 때 95.6%의 ee값을 가지는 S-ester로 분할되었다. 전환율은 온도 $50^{\circ}C$, pH 7.0에서 가장 높게 나타났고, 광학선택성은 온도, pH에 의해 영향을 받지 않았다. 용매의 첨가에 의해 전환율은 감소하였으나 광학선택성은 약간 증가하였다. 기질농도가 증가함에 따라 광학선택성은 감소하였고, 이것은 가수분해반응 생성물에 의한 영향으로 확인되어 반응 생성물을 제거함으로써 광학선택성을 증가시킬 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.85-94
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• 1994

Lipase (triacylglycerol hydrolase, EC 3.1.1.3) is able to catalyze the hydrolysis of ester bonds of triacylglycerols at the interface between aqueous phase and organic phase containing substrate. With the rapid development of lipid biotechnology, lipase-catalyzed hydrolysis of lipids has a great concern from the industrial point of view. Owing to the reversible nature of the lipase, the reactions are also applied for glyceride synthesis, interesterification and resolution of racemic mixtures into optically active alcohols or acids. For all applications of the lipases, a reliable method for the determination of enzyme activity is required. Precise quantitative determination of its activity is essential as the basis of research and development of the bioprocess involving the enzyme. This article reviews the existing literature on the detection and determination of lipase activity from microbial, mammalian and plant sources.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.836-839
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• 2000

Beef tallow, which is an industrial lipid substrate, was hydrolyzed by lipase immobilized on a high-density polyethylene (HDPE) powder. Ethanol pre-washing process affected the immobilization efficiency. Half-life of storage of the HDPE at $4^{\circ}C$ was 150 days. And after 10 times of repeated use, more than 50% of initial activity remained. An apparent Michaelis constant ($K_m$) and maximum velocity ($V_{max}$) were 2.7M, and 1.4 mmol/min/l for immobilized lipase, and 0.5 M, and 1.9 mmol/min/l for soluble lipase, respectively.

• BMB Reports
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• 제34권3호
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• pp.274-277
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• 2001

Lipase of Staphylococcus sp. was purified from the culture supernatant, and its molecular mass estimated to be 44 kDa by SDS-PAGE. Its optimum temperature and pH for the hydrolysis of p-nitrophenyl substrates was $28^{\circ}C$ and pH 8.5, respectively The gene encoding the lipase was cloned in Escherichia coli in the $NH_2$-teminally truncated form by using the shotgun method, and sequenced. The mature enzyme had a 49-93% amino acid sequence homology with other staphylococcal lipases. This lipase was used for the hydrolysis of the 3-O-acetate of cephalosporin-C to give an intermediate, deacetylated cephalosporin-C that is useful for further chemical elaborations.

• Macromolecular Research
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• 제16권7호
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• pp.651-658
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• 2008

Poly(butylene succiate) (PBS), poly(butylene succinate-co-L-lactate) (PBSL), and poly(butylene succinate-co-6-hydroxycaproate) (PBSCL) polymers were degraded by lipase $PS^{(R)}$, and the enzymatic degradation mechanism of PBS was analyzed in detail. The enzymatic degradation of PBS gave 4-hydroxybutyl succinate (4HBS) as the main product. An exo-type hydrolysis mechanism was proposed based on this observation. The terminal chain of PBS had conformational similarity to ordinary tri- and diglycerides and could be incorporated as a substrate in the active site of this lipase. The surface adsorption of the lipase was much larger on PBS and its copolymer films than on the other polyester films because the lipase adhered quite strongly to the polymer terminal through a specific adsorption mechanism. Kinetic analysis showed that the total number of surface adsorption points per unit area of PBSL and PBSCL copolymers was larger than that of the PBS homopolymer.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권2호
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• pp.57-66
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• 2002

This review focuses on the use of immobilized lipase technology for the hydrolysis of oils. The importance of lipase catalyzed fat splitting process, the various immobilization procedures, kinetics, deactivation kinetics, New immobilized lipases for chiral resolution, reactor configurations, and process considerations are all reviewed and discussed.

• KSBB Journal
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• 제13권1호
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• pp.90-95
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• 1998

Candida cylindracea유래의 리파제인 lipase-OF 360,000를 이용한 다중불포화지방산의 농축공정개발에 관한 연구를 수행하 였다. Lipase-OF 360,000은 5가지 종류에 대한 유지의 가수분해에서 다중불포화지방산인 n-3족 아실기를 다량 함유하는 물고기기름에 대해서만 낮은 활성을 보였다. 이 리파제에 의한 물고기기름의 가수분해에서 반응이 진행됨에 따라 DHA는 계속 농축되는 양상을 보이지만 EPA의 경우는 가수분해반응이 0-30% 진행시까지는 완만하게 농축이 진행되다가 30-50% 진행되는 동안은 더 이상의 농축이 진행되지 않았고 약 50% 이상부터는 감소하기 시작하여 반응 완료시에는 반응전 물고기기름에 있어서 EPA의 함량과 거의 비슷한 약 18% 정도로 감소되었다. 이러한 양상은 기질에 대한 Lipase-OF 360,000의 농도에 상관없이 거의 유사하게 일어났다. 본 연구결과로서 Lipase-OF 360,000의 아실 체인 특이성을 두 가지로 요약할 수 있는데 첫 번째는 가수분해에 있어서 물고기기름내의 n-3족 다중불포화지방산과 그 외의 다른 지방산들의 차별성이다. Lipase-OF 360,000은 n-3족 다중불포화지방산에 대해서만 현저히 낮은 활성을 보였다. 두 번째는 n-3족 다중불포화지방산이 가지는 구조적 차이가 Lipase-OF 360,000의 특이적 활성에 미치는 영향이다. 이 경우는 n-3족 다중불포화지방산내의 탄소수와 불포화도가 높을수록 Lipase-OF 360,000의 활성이 좋지 않았다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.465-470
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• 2004

Optimal conditions for the in situ immobilization of lipase in aldehyde-silica packed columns, via reductive amination, were investigated. A reactant mixture, containing lipase and sodium borohydride (NaCBH), was recirculated through an aldehyde-silica packed column, such that the covalent bonding of the lipase, via amination between the amine group of the enzyme and the aldehyde terminal of the silica, and the reduction of the resulting imine group by NaCBH, could occur inside the bed, in situ. Mobile phase conditions in the ranges of pH $7.0{\~}7.8$, temperatures between $22{\~}28^{circ}C$ and flow rates from $0.8{\~}1.5\;BV/min$ were found to be optimal for the in situ immobilization, which routinely resulted in an immobilization of more than 70 mg­lipase/g-silica. Also, the optimal ratio and concentration for feed reactants in the in situ immobilization: mass ratio [NaCBH]/[lipase] of 0.3, at NaCBH and lipase concentrations of 0.75 and 2.5 g/L, respectively, were found to display the best immobilization characteristics for concentrations of up to 80 mg-lipase/g-silica, which was more than a 2-fold increase in immobilization compared to that obtained by batch immobilization. For tributyrin hydrolysis, the in situ immobilized lipase displayed lower activity per unit mass of enzyme than the batch-immobilized or free lipase, while allowing more than a $45\%$ increase in lipase activity per unit mass of silica compared to batch immobilization, because the quantity of the immobilization on silica was aug­mented by the in situ immobilization methodology used in this study.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.332-339
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• 2010

The lipase from Mucor racemosus NRRL 3631 was partially purified by fractional precipitation using 60% ammonium sulfate, which resulted in a 8.33-fold purification. The partially purified lipase was then immobilized using different immobilization techniques: physical adsorption, ionic binding, and entrapment. Entrapment in a 4% agar proved to be the most suitable technique (82% yield), as the immobilized lipase was more stable at acidic and alkaline pHs than the free enzyme, plus 100% of the original activity was retained owing to the thermal stability of the immobilized enzyme after heat treatment for 60 min at $45^{\circ}C$. The calculated half-lives (472.5, 433.12, and 268.5 min at 50, 55, and $60^{\circ}C$, respectively) and the activation energy (9.85 kcal/mol) for the immobilized enzyme were higher than those for the free enzyme. Under the selected conditions, the immobilized enzyme had a higher $K_m$ (11.11 mM) and lower $V_{max}$ (105.26 U/mg protein) when compared with the free enzyme (8.33 mM and 125.0 U/mg protein, respectively). The operational stability of the biocatalyst was tested for both the hydrolysis of triglycerides and esterification of fatty acids with glycerol. After 4 cycles, the immobilized lipase retained approximately 50% and 80% of its original activity in the hydrolysis and esterification reactions, respectively.