• 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.

• Journal of Life Science
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• v.13 no.5
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• pp.723-731
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• 2003

For the investigation of conserved regions in lipase genes, 132 and 24 sequences were obtained from LED (Lipase Engineering Database) and COG (Clusters of Orthologous Groups of proteins), respectively. There was high diversity in lipase genes and peculiar amino acid sequences were conserved for each homologous family of LED. Similar conserved amino acid sequences were detected from COG0657 and Moraxella lipase 1 homologous group of LED. Although many studies have attempted to detect new lipase genes in procaryotes, they have been limited culturable bacteria. The importance of metagenome, including DNA from non-culturable bacteria, is known. Due to the high diversity, we assumed it might be possible to detect new lipase gene from metagenome. Due to the high diversity of nucleotide sequences in lipase genes, 10 primer sets were designed. Designed primer sets were inspected in BLAST of NCBI and they could amplify a part of the lipase gene from 222 to 713 bp. They can amplify 16.7%∼60.0% of each lipase homologous group which was 3.6 fold higher than each sets. They might offer a high probability of detecting new lipase genes, owing to high efficiency and the diversity of lipase genes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.40-45
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• 1991

The release of hepatic triglyceride lipase from cultured rat hepatocytes and its hormonal regulation were studied. The activity of lipase released into the medium in the presence of heparin was increasing during 24 hours on the 2nd of culture while this was 10% in the absence of heparin as compared with the lipase activity in the presense of heparin. When hepatocytes were cultured with anti-hepatic triglyceride lipase lgG the lipase activity was supp-ressed by 92% The results suggest that the enzyme relaeased into culture medium is identical to hepatic triglyceride lipase which can be released only in the presence of heparin the model of release being similar to that of lipoprotein lipase from adipocytes. The addition of monensin to the medium resulted in The inhibition of lipase secretion by 61% Insulin enhanced lipase activity only 20% whereas dexamethasone suppressed the activity by 44% These data inidica-ted that hepatic triglyceride lipase is secreted and released from hepatocytes in the presence of heparin and its secretion is regulated by hormones.

• Fibers and Polymers
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• v.7 no.4
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• pp.339-343
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• 2006

The aim of this paper is to improve moisture regain of PET fabrics using a lipase treatment. Effects of nine lipase sources, lipase activator and nonionic surfactant on moisture regain of PET fabrics are examined. Moisture regains of lipase-treated samples improve by two times in average compared with untreated and buffer-treated samples. Alkaline treatment creates larger pitting by more aggressive attack into fiber which is proved by SEM and water contact angle measurement. Moisture regain by alkaline treatment ($0.568%{\pm}0.08$) does not improve. However, lipase-treatment (L2 treatment) improves moisture regain up to 2.4 times ($1.272%{\pm}0.05$). Although lipase treatment is more moderate than alkaline treatment, lipase hydrolysis on PET fabrics improves moisture regain, efficiently. K/S values improved confirm that carboxyl and hydroxyl groups are produced on the surface of PET fabrics by lipase hydrolysis. Moisture regain and dyeability improve by lipase hydrolysis on PET fabrics.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.650-654
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• 2007

In our previous work, a method of pretreating lipase was developed to prevent loss of its activity during covalent immobilization. In this study, Rhizopus oryzae lipase was pretreated before immobilization and then immobilized on a silica gel surface. The effects of the various materials and conditions used in the pretreatment stage on the activity of immobilized lipase were investigated. Immobilized lipase pretreated with 0.1% of soybean oil had better activity than those pretreated with other materials. The optimal temperature, agitation speed, and pretreating time for lipase pretreatment were determined to be $40^{\circ}C$, 200rpm, and 45min, respectively. The activity of immobilized soybean oil pretreated lipase was 630U/g matrix, which is 20 times higher than that of immobilized non-pretreated lipase. In addition, immobilized lipase activity was maintained at levels exceeding 90% of its original activity after 10 reuses.

• KSBB Journal
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• v.14 no.6
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• pp.696-701
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• 1999

The enzymatic hydrolysis of Castor oil for the mass production of ricinoleic acid was studied to find out the optimum conditions such as solvents and the weight ratio of substrate to enzyme. Three different lipases were tested for the hydrolysis of castor oil: lipase from Porcine Pancrease(lipsase PP), lipase from Candida cylindracea(lipase CC), lipase from Candida Rugosa(lipase CR). The poor mass transfer in water caused a low degree of hydrolysis of castor oil. To overcome this problem, organic solvents were used. Among organic solvents tested, hydrophobic solvents gave better results of hydrolysis than hydrophilic solvents. Organic solvents also lowered or changed the effect of pH. Isopropyl ether made complete hydrolysis of castor oil. The ratio of water to isopropyl ether and the ratio of weight ratio of lipase to castor oil were important for the hydrolysis of castor oil. At 30$^{\circ}C$ castor oil was completely hydrolyzed by 4 wt% of lipase in the mixture of isopropyl ether and water(1:1 in volume).

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.315-322
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• 2014

Immobilized lipases were prepared by physical adsorption using lipase AK, AY, AH, PS and R on Amberlite$^{(R)}$XAD$^{(R)}$7 HP resin. With the immobilized lipases (10%), structured lipid was synthesized by enzymatic interesterification of canola oil, palmitic ethyl ester, and stearic ethyl ester in order to study the reaction characteristics. Among the lipase, the highest protein content was obtained from lipase AH (11.41%) before immobilization, while the highest levels of bound protein was observed from immobilized lipase AK (63.91%). Immobilized lipase AK had the highest interesterification activity (38.3% of total saturated fatty acid). Lipase AK was also used for a continuous reaction in which the slow flow of reactant resulted in increased reaction rate. Reusability of immobilized AK, AH and PS increased at the second reaction (120-196.5%). However, the activity of immobilized AK, which had the highest bound protein content (63.91%) decreased after the third reaction, while the activity of immobilized AH and PS was maintained until the sixth reaction.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.14-19
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• 2009

This study was performed to characterize the lipases produced from Gelidibacter sp. YH333 and Vibrio sp. YH339 isolated from mud flats for industrial application of a lipase. Amount of the lipases secreted from the isolated strains was sharply increased in the proportion of increase of number of the cells. The lipases produced from the isolated strains were constitutively secreted from the cells. The lipase activity of Gelidibacter sp. YH333 was higher than that of Vibrio sp. YH339 to p-nitrophenyl esters. The lipases produced from both strains showed the highest activity in p-nitrophenyl laulate among various p-nitrophenyl esters. The molecular weights of the lipases from Gelidibacter sp. YH333 were about 50 KDa and 25 KDa, respectively. Molecular weight of the lipase from Vibrio sp. YH339 was about 50 KDa.

• Bulletin of Food Technology
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• v.7 no.2
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• pp.64-73
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• 1994

Using 20 lipases from various microbial origins medium chain glycerides, namely, mono-, di-, and tri-carproyl glycerols from glycerol and acid were synthesized in isooctane. Enzyme reaction was performed at 0.35 M of capric acid, 0.025M of glycerol and the same mass of silica gel to remove water in 5ml of isooctane with 30mg of lyophilized lipase. Among 20 lipases, eleven lipases showed good synthetic activities, especially lipase from Pseudomonas aeruginosa (Lipase PS), Rhizomucor miehei origined lipase and Chromobacterium viscosum lipase (Lipase CV) showed good activities for production of tricaproylglycerol, while Lipase OF-360 (origined from Candida rugosa) and Lipase D (Rhizopus delemar) were good for production of dicaprolyglycerol. The lipases, especially Lipase PS, have high thermal stability at $ 60^{circ}C$, and optimum pH of lyophilization for dehydrating the lipase was pH 6.5.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.75-80
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• 1985

To utilize lipase obtained from Candida cylindracea for lipid hydrolysis, methods to immobilize lipase by adsorption and reaction characteristics of the immobilized lipase by adsorption were investigated. Among the tested adsorbents, silica gel was selected as a suitable adsorbent. The optimum condition for adsorption of lipase was when 47.5 units of lipase were adsorbed to 1.6g of silica gel at pH7.0 and $5^{\circ}C$ for 100 min. Optimum pH and temperature for activity of the immobilized lipase were at $37^{\circ}C$ and pH7.0, which were same as the soluble lipase. Optimum enzyme concentration of the immobilized lipase were 30g for milk fat and 80g for olive oil, whereas those of the soluble lipase were 800 units for milk fat and 1200 units for olive oil. The optimum substrate concentrations of the immobilized and soluble lipases were 20% lipid, regardless of lipid types. Rapid hydrolysis of milk fat was observed with the soluble lipase for the initial 4 hours and with the immobilized lipase for the initial 8 hours. The immobilized lipase produced same amount of capric acid as the soluble lipase, but more myristic acid and less butyric acid than the soluble lipase.