• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.4
• /
• pp.329-333
• /
• 2005

This study was designed to investigate the stability of a lipase fused with a cellulose­binding domain (CBD) to cellulase. The fusion protein was derived from a gene cluster of a CBD fragment of a cellulase gene in Trichoderma hazianum and a lipase gene in Bacillus stearother­mophilus L1. Due to the CBD, this lipase can be immobilized to a cellulose material. Factors affecting the lipase stability were divided into the reaction-independent factors (RIF), and the re­action-dependent factors (RDF). RIF includes the reaction conditions such as pH and tempera­ture, whereas substrate limitation and product inhibition are examples of RDF. As pH 10 and $50^{\circ}C$ were found to be optimum reaction conditions for oil hydrolysis by this lipase, the stability of the free and the immobilized lipase was studied under these conditions. Avicel (microcrystal­line cellulose) was used as a support for lipase immobilization. The effects of both RIF and RDF on the enzyme activity were less for the immobilized lipase than for the free lipase. Due to the irreversible binding of CBD to Avicel and the high stability of the immobilized lipase, the enzyme activity after five times of use was over $70\%$ of the initial activity.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.24 no.2
• /
• pp.205-213
• /
• 2000

This study investigated the effect of mixing protease and lipase on detergency. The detergency of protein soiled, oil soiled and protein-oil soiled cloths and the relative hydrolytic activity of enzymes were examined. The protease-lipase added detergent solution was most effective for the removal of protein in protein-oil soiled cloths. This is because the lipase removed the protein that was physically bound to oil as well as the protease removed the protein. The protease added detergent solution was second effective, the lipase added detergent solution was third effective, and the detergent solution without protease and lipase was the least effective. The protease-lipase added detergent solution was also most effective in the oil removal from protein-oil soiled cloths. Unlike in protein removal, however, the protease added detergent solution was more effective in oil removal than the lipase added detergent solution. This is because the removal of oil bound to protein by protease was more effective than the removal of oil by lipase. In soiling-washing cycles, however, the effects of lipase increased, and as a result, the detergency of protease added detergent solution and the lipase added detergent solution became similar.

• Korean Journal of Food Science and Technology
• /
• v.17 no.2
• /
• pp.60-64
• /
• 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 the Korean Society of Clothing and Textiles
• /
• v.33 no.7
• /
• pp.1121-1127
• /
• 2009

This study presents an eco-friendly and one-step finishing method for modifying fiber property that reduces fiber damage in wool/polyester blend fabrics. Lipase from aspergillus oryzae is used in this experiment. The enzymatic treatment condition is optimized by measuring the relative activity of lipase depending on pH level, temperature, concentration of lipase, and treatment time. The concentration of $CaCl_2$as an activator is determined by the characteristics including whiteness, water contact angle (WCA), and dyeing property. The modified properties of lipase treated fabrics are tested for pill resistance and surface morphology. The results are described as follows: the optimum condions for lipase treatment constitute a pH level of 8.0, treatment temperature of 40$^{\circ}$$_C$, concentration of lipase at 100% (o.w.f), and a treatment time of 90 minutes. $CaCl_2$helps in raising lipase activation, and the optimum concentration is 50mM. The whiteness, wet ability, and pill resistance of lipase treated fabrics improves as compared to the control. The dyeing property of lipase treated fabrics improved by 53.5% after using the one-bath dyeing method. This means that lipase treatment can save time and cost during the dyeing process since lipase treatment modifies wool and polyester fibers. The surface of lipase treated wool fibers do not exhibit any change, however voids and cracks manifest on the surface of lipase treated polyester fibers.

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

• Microbiology and Biotechnology Letters
• /
• v.49 no.3
• /
• pp.337-345
• /
• 2021

Lipase (triacylglycerol lipase, EC 3.1.1.3) is an enzyme capable of hydrolyzing triacylglycerol, to produce fatty acids and glycerol and reverse the reaction of triacylglycerol synthesis from fatty acids and glycerol through transesterification. Applications of lipase are quite widespread in the industrial sector, including in the detergent, paper, dairy, and food industries, as well as for biodiesel synthesis. Lipases by yeasts have attracted industrial attention because of their fast production times and high stability. In a previous study, a lipase-producing yeast isolate was identified as Zygosaccharomyces mellis SG1.2 and had a productivity of 24.56 U/mg of biomass. This productivity value has the potential to be a new source of lipase, besides Yarrowia lypolitica which has been known as a lipase producer with a productivity of 0.758 U/mg. Lipase production by Z. mellis SG1.2 needs to be increased by optimizing the production medium. The aims of this study were to determine the significant component of the medium for lipase production and methods to increase lipase production using the optimum medium. The two methods used for the statistical optimization of production medium were Taguchi and RSM (Response Surface Methodology). The data obtained were analyzed using Minitab 18 and SPSS 23 software. The most significant factors which affected lipase productivity were olive oil and peptones. The optimum medium composition consisted of 1.02% olive oil, 2.19% peptone, 0.05% MgSO₄·7H₂O, 0.05% KCl, and 0.2% K₂HPO₄. The optimum medium was able to increase the lipase productivity of Z. mellis SG1.2 to 1.8-fold times the productivity before optimization.

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

• Journal of Microbiology and Biotechnology
• /
• v.26 no.1
• /
• pp.80-88
• /
• 2016

The enzyme-catalyzed Henry reaction was realized using deep eutectic solvents (DESs) as a reaction medium. The lipase from Aspergillus niger (lipase AS) showed excellent catalytic activity toward the substrates aromatic aldehydes and nitromethane in choline chloride:glycerol at a molar ratio of 1:2. Addition of 30 vol% water to DES further improved the lipase activity and inhibited DES-catalyzed transformation. A final yield of 92.2% for the lipase AS-catalyzed Henry reaction was achieved under optimized reaction conditions in only 4 h. In addition, the lipase AS activity was improved by approximately 3-fold in a DES-water mixture compared with that in pure water, which produced a final yield of only 33.4%. Structural studies with fluorescence spectroscopy showed that the established strong hydrogen bonds between DES and water may be the main driving force that affects the spatial conformation of the enzyme, leading to a change in lipase activity. The methodology was also extended to the aza-Henry reaction, which easily occurred in contrast to that in pure water. The enantioselectivity of both Henry and aza-Henry reactions was not found. However, the results are still remarkable, as we report the first use of DES as a reaction medium in a lipase-catalyzed Henry reaction.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.6
• /
• pp.832-838
• /
• 1999

Two different types of lipases (lipase I and lipase II) secreted into culture medium by Rhizopus sp. L-I were purified using a hydrophobic chromatography and were partially characterized. Both enzymes were monomeric as revealed by SDS-PAGE and gel filtration. The molecular masses of the enzymes were identified as 45 kDa (lipase I) and 69 kDa (lipase II). The isoelectric points were estimated to be 3.6 and 5.2 for lipase I and lipase II, respectively. pH and temperature activity optima for lipase I were as 7.5 and $50^{\circ}C$, respectively, whereas the corresponding parameters for lipase II were 6.0 and $45^{\circ}C$. The amino terminal sequences of lipase I and lipase II, determined by Edman degradation, were found to be Leu-Val-Met-Ile-Gln-Arg and Leu-Val-Met-Lys-Gln-Arg, respectively. By western blotting analysis, the two lipases were found to have a common antigenic determinant. Immuno-electron cytochemistry conducted with polyclonal anti-lipase I antibody indicated the enzyme located in both the periplasm and the adjacent vesicles of fungal hyphae. Fortunately, the sites on the cell envelope where lipase was exported into the culture medium was also identified.

• Korean Journal of Food Science and Technology
• /
• v.8 no.1
• /
• pp.33-41
• /
• 1976

These experiment were conducted to investigate the cultural condition of the lipase production by Rhizopus japonicus. The results obtained were as follows: 1. Soybean meal and ammonium sulfate were the most effective in the lipase production as organic and inorganic nitrogen sources, respectively. 2. The lipase production was strongly inhibited, when added as carbon sources xylose, glucose, fructose, galactose, maltose, soluble starch, and dextrin causing the lowering of pH of the medium during culture. Sucrose did not inhibit the lipase production, but not caused any effect when added. 3. $K_2HPO_4$ as phosphate salt and $MgSO_4{\cdot}7H_2O$ as magnesium salt were the most effective in the lipase production. 4. The addition of olive oil, soybean oil, and coconut oil respectively increased the enzyme production and especially 1% olive oil increased it by 50%. 5. The enzyme production increased slightly on the addition of yeast extract to $0.05{\sim}0.07%$. 6. The optimum composition of the medium for the lipase production by Rhizopus japonicus was in the composition of soybean meal 2%; $K_2HPO_4{\cdot}$ 0.5%; $(NH_4)_2SO_4$ 0.1%; $MgSO_4\;7H_2O$ 0.05%; yeast extract 0.05%; olive oil 1%. The maximum production of the lipase was attained by the incubation far 48hrs under the optimum incubation condition.