• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.60-64
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• 1985

To utilize microbial lipases for hydrolysis of milk fat, optimum reaction conditions and characteristics of enzymatic reactions of lipases originated from Rhizopus delemar, Mucor sp., and Candida cylindracea were investigated. Optimum pH and temperature were pH 5.6 and $45^{\circ}C$ for Rhizopus delemar lipase, pH7.5 and $35^{\circ}C$ for Mucor sp. lipase, and pH7.5 and $35^{\circ}C$ for Candida cylindracea lipase. Optimum lipase concentration and optimum substrate concentration were $600{\sim}800\;units/ml$ and 20% milk fat, regardless of their origin. Km values were 6.06% milk fat for Rhizopus delemar lipase, 7.69% for Mucor sp. lipase and 7.99% for Candida cylindracea lipase. Rate of lipid hydrolysis was Rhizopus delemar lipase>Mucor sp. lipase>Candida cylindracea lipase. As the reaction time was extended, liberation of short chain fatty acids was increased. After 8 hours reaction, capric acid content significantly increased with Candida cylindracea lipase, palmitic acid with Mucor sp. lipase and butyric acid with Rhizopus delemar lipase.

• Food Science of Animal Resources
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• v.20 no.2
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• pp.101-106
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• 2000

Effects of Ph on the activity of lipase isolated from milk fat globules were investigated, using coconut oil and homogenized milk as substrate. With buttermilk as an enzyme source for coconut oil and homogenized milk substrates bell-shaped curve was observed at $37^{\circ}C$, having the highest activity at pH 9.5. However, lipase activity at $0^{\circ}C$ continuously increased up to pH 10.0. With the purified lipase for homogenized milk substrate, the bell -shaped curve and the highest activity were observed at $37^{\circ}C$ and pH 9.0, respectively. Lipase activity at $0^{\circ}C$ increased up to pH 10.0. The addition of bovine serum albumin to the coconut oil shifted the optimum pH to pH 9.5 and the activity remarkably declined at pH 10.0. The effect of pH on the stability of purified lipase was depending on the temperature. Wehn the lipase kept at $37^{\circ}C$ for 20 minutes, it's activity remarkably declined as pH increased: the activity at pH 10.0 was declined by 13% of that pH 8.5. However, when the lipase kept at $4^{\circ}C$ for 60minutes, the activity was stable within the range of pH 7.5 to 10.0.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.101-104
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• 1977

Lipase from Geotrichum candidum was heat inactivated in 0.1M phosphate buffer solution. The thermal inactivation followed first order kinetics for the range of temperatures $50^{\circ}-80^{\circ}C$ except at $50^{\circ}C$. The changes in enthalpy, entropy and Gibbs free energy at $60^{\circ}C$ were 120.4 kJ/mol, 73.0 J/mol K and 96.9 kJ/mol respectively a value of $19^{\circ}C$(Geotrichum candidum lipase) is greater than that of lipases from milk and pancreas. The effect of detergents, lecithin and linoleic acid or the thermal inactivation of lipase was found to be negligible.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.873-877
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• 2004

The relationship between the behaviors of c.c.lipase back-extraction and their percolation phenomena by using AOT reverse micellar systems (RVMS) has been studied by the addition of a small amount of additives to organic phase such as thiols and nonionic-surfactants focusing on micelle-micelle interactions. The values of ${\beta}_t$ defined by the variation of percolation processes and back-extraction behaviors of c.c.lipase have a good linear correlation. The hydrophobicity of additive molecules suppressing the cluster formation of reverse micelles (high values of ${\beta}_t$) improved the back-extraction behavior of c.c.lipase. The back-extraction fraction and its rate of c.c.clipase are increased with decreasing of the value of hydrophilic lipophilic balance (HLB) and increasing of the hydrophobicity per additive molecules added to reverse micellar systems (RVSM) in the same additives concentration.

• The Korean Journal of Food And Nutrition
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• v.8 no.3
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• pp.192-198
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• 1995

For the production of EMC, various professes and lipases were used to hydrolyse cheese sulk. The optimal conditions of various proteases were as follows, pronase-3$0^{\circ}C$, p14 7.0, pancreatln-4$0^{\circ}C$, pH 8.0, pacific protease-3$0^{\circ}C$, pH 7.0 and protease from Asp. sp. -5$0^{\circ}C$, pH 8.0. The optimal conditions of various lipases were as follows ; pancreatic lipase-5$0^{\circ}C$, pH 8.0, palatase ML-5$0^{\circ}C$, pH 7.0 and lipase form Candida -4$0^{\circ}C$, pH U.0. After hydrolysation under optimal conditions, the amounts of free amino acid and free fatty ac14 were increased with reaction time. Hydrolysates of pacific protease and pronase were showed high amount of free amino acid(0.67mg/ml and 0.74mg/ml). Especially EMC had high amount of glutamic acid and leucine. Lipase from Candida cylindracea produced high amount of free fatty acid (24.63 mg/ml) Butyric acrid, palmitic acid, stearic acid and oleic acid among free fatty acids were showed high amounts. Sensory evaluation of various MC were tasted nth 8 panelist. EMC produced with pancreatic lipase was most bitterness and EMC produced with palatase ML was best acceptable cheese flavor.

• BMB Reports
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• v.34 no.3
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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.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.98-103
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• 2012

For screening of useful enzymes producing microorganisms from Meju, we isolated high lipase producing strains and their lipolytic enzyme activities were then tested. The lipolytic enzyme activities of isolated microorganisms were therefore tested on the Y124 strain. The gene sequence analysis of ITS from Y124 strain revealed Yarrowia lipolytica. Lipase production by the Y124 strain was studied in media containing various carbon sources. The Y124 strain drastically increased lipolytic enzyme activity in YPO media containing olive oil, as well as in YPDO media containing both olive oil and glucose. Maximal lipase production was achieved in YPD (yeast extract-peptone-D-glucose) media containing 0.7% olive oil when cultured at $30^{\circ}C$ for 8 hrs. The lipase produced from the Y124 strain showed the highest activity in p-NPO (p-nitrophenyl octanoate ($C_8$)), amongst the various p-nitrophenyl esters.

• KSBB Journal
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• v.10 no.5
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• pp.575-581
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• 1995

A plasmid pTTY2, containing the lipase-producing gene, was used to transform an E. coli phage lysogen, P90c/$\phi$434, into the lipase-producing lysogen, P90c/$\phi$434/pTTY2. After the overproduction of lipase by the isopropylthio-${\beta}$-D-galactoside induction, the prophage $\phi$434 in the chromosome of the host cell was induced by the milomycin C addition or ultraviolet irradiation to lyse the host cell. The optimum operating conditions, such as the isopropylthio-${\beta}$-D-galactoside induction period and the phage induction timing, were sought for the efficient cell lysis in the same fermenter. Effective cell lysis occurred at the earlier exponential growth phase with the isopropylthio-${\beta}$-D-galactoside induction period of 1 hour. The amount of the lipase production was qualitatively measured by the halo size in Luria-Bertani agar medium containing tributyrin and Rhodamine B plate.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.128-135
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• 2009

Acinetohacter baumannii BD5 was isolated from waters of Baek-du mountain, and the lipase gene was cloned using a PCR technique. The deduced amino acid sequence of the lipase and lipase chaperone were found to encode proteins of 325 aa and 344 aa with a molecular mass of 35 kDa and 37 kDa, respectively. The lipase gene was cloned and expressed in Escherichia coli BL21(trxB) as an inclusion body, which was subsequently solubilized by urea, and then purified using Ni-affinity chromatography. After being purified, the lipase was refolded by incubation at $4^{\circ}C$ in the presence of a 1:10 molar ratio of lipase:chaperone. The maximal activity of the refolded lipase was observed at a temperature of $35^{\circ}C$ and pH 8.3 when p-NP caprate(C10) was used as a substrate; however, 28% of the activity observed at $35^{\circ}C$ was still remaining at $0^{\circ}C$. The stability of the purified enzyme at low temperatures indicates that it is a cold-adapted enzyme. The refolded lipase was activated by $Ca^{2+},\;Mg^{2+},\;and\;Mn^{2+}$, whereas $Zn^{2+}\;and\;Cu^{2+}$ inhibited it. Additionally, 0.1% Tween 20 increased the lipase activity by 33%, but SDS and Triton X-100 inhibited the lipase activity by 40% and 70%, respectively.

• Korean Journal of Food Science and Technology
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• v.8 no.4
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• pp.242-246
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• 1976

These experiment were conducted to investigate the characteristics of the purified lipase of Rhizopus japonicus. 1. The optimum pH for the lipase action was 6.8, the stable pH ranged $5.0{\sim}8.0$ and the optimum temperature was $35^{\circ}C$. The Purified lipase was stable below $45^{\circ}C$ and inactivated abruptly above $45^{\circ}C$ 2. Coconutoil castor oil and palm oil were most favorably hydrolyzed by the purified lipase, wheres olive oil and soybean oil were slightly less than the former three, and Tween 80 was hydrolyzed only 30% compared with coconut oil. 3. The purified lipase was activated by $Ca^{++}$ and $Mg^{++}$, whereas it was inhibited by $Hg^{++}$ and $Fe^{++}$.