• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.151-156
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• 1997

Two commercially available lipases, Lipase OF (non-specific lipase from Candida rugosa) and Lipolase 100T (1, 3-specific lipase from Aspergillus niger), were immobilized on insoluble hydrophobic support HDPE (high density polyethylene) by the physical adsorption method. Hydrolysis performance was enhanced by mixing a non-specific Lipase OF and a 1, 3-specific Lipolase 100T at a 2 : 1 ratio. The results also showed that the immobilized lipase maintained its activity at broader temperature ($25~55^{\circ}C$) and pH (4-8) ranges than soluble lipases. In the presence of organic solvent (isooctane), the immobilized lipase retained most of its activity in upto 12 runs of hydrolysis experiment. However, without organic solvent in the reaction mixture, the immobilized lipase maintained most of its activity even after 20 runs of hydrolysis experiment.

• KSBB Journal
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• v.6 no.4
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• pp.337-344
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• 1991

The liquid-liquid extraction of lipase A from Candide cylindracea and lipase B from porcine pancrease was carried out using reversed micellar organic solvents. Effects of various factors such as ionic strength, pH, and species and concentration of surfactant, on lipase solubilization were studied. A cationic surfactant cetyl-trimethyl ammonium bromide (CTAB) in isooctane/nhexanol(1:1) was found to be an effective solvent and its optimum concentration was 50 mM. KCl among various salts tested was the most effective and the efficiency of solubilization of lipase increased with decreasing the ionic strength of salts. The maximum activity and solubiliz ation of protein were obtained at pH 8. The stripping efficiency has a maximum value at pH 4 and increases with KCl concentration in the range of 0.2∼1.0 M. After the solubilization and stripping, the overall recovery efficiency of mass and specific activity of lipases was 62% and 66%, respectively.

• Genomics & Informatics
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• v.9 no.2
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• pp.79-84
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• 2011

Two initial models of cold-adapted lipase PsLip1 have been constructed, based on homology with the bacterial lipases Chromobacterium viscosum (CvLip) and Pseudomonas cepacia (PcLip), whose X-ray structures have been solved and refined to high resolution. The mature polypeptide chains of these lipases have 84% similarity. The models of Mod1 and Mod2 have been compared with the tertiary structures of CvLip and PcLip, respectively, and analyzed in terms of stabilizing interactions. Several structural aspects that are believed to contribute to protein stability have been compared: the number of conserved salt bridges, aromatic interactions, hydrogen bonds, helix capping, and disulfide bridges. The 3-dimensional structural model of PsLip1 has been constructed in order to elucidate the structural reasons for the decreased thermostability of the enzyme in comparison with its mesophilic counterparts.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.6
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• pp.522-525
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• 2006

Biodiesel conversion from soybean oil reached a maximum of 70% at 18 h using immobilized 1,3-specific Rhizopus oryzae lipase alone. Biodiesel conversion failed to reach 20% after 30 h when immobilized nonspecific Candida rugosa lipase alone was used. To increase the biodiesel production yield, a mixture of immobilized 1,3-specific R. oryzae lipase and nonspecific C. rugosa lipase was used. Using this mixture a conversion of greater than 99% at 21 h was attained. When the stability of the immobilized lipases mixture was tested, biodiesel conversion was maintained at over 80% of its original conversion after 10 cycles.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.142-146
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• 2005

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1054-1057
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• 2007

Lipases are industrially useful versatile enzymes that catalyze numerous different reactions including hydrolysis of triglycerides, transesterification, and chiral synthesis of esters under natural conditions. Although lipases from various sources have been widely used in industrial applications, such as in food, chemical, pharmaceutical, and detergent industries, there are still substantial current interests in developing new microbial lipases, specifically those functioning in abnormal conditions. We screened 17 lipase-producing yeast strains, which were prescreened for substrate specificity of lipase from more than 500 yeast strains from the Agricultural Research Service Culture Collection (Peoria, IL, U.S.A.), and selected Yarrowia lipolytica NRRL Y-2178 as a best lipase producer. This report presents new finding and optimal production of a novel extracellular alkaline lipase from Y. lipolytica NRRL Y-2178. Optimal culture conditions for lipase production by Y. lipolytica NRRL Y-2178 were 72 h incubation time, $27.5^{\circ}C$, pH 9.0. Glycerol and glucose were efficiently used as the most efficient carbon sources, and a combination of yeast extract and peptone was a good nitrogen source for lipase production by Y. lipolytica NRRL Y-2178. These results suggested that Y. lipolytica NRRL Y-2178 shows good industrial potential as a new alkaline lipase producer.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.888-897
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• 2009

Lipase diversity in glacier soil was assessed by culture-independent metagenomic DNA fragment screening and confirmed by cell culture experiments. A set of degenerate PCR primers specific for lipases of the hormone-sensitive lipase family was designed based on conserved motifs and used to directly PCR amplify metagenomic DNA from glacier soil. These products were used to construct a lipase fragment clone library. Among the 300 clones sequenced for the analysis, 201 clones encoding partiallipases shared 51-82% identity to known lipases in GenBank. Based on a phylogenetic analysis, five divergent clusters were established, one of which may represent a previously unidentified lipase subfamily. In the culture study, 11 lipase-producing bacteria were selectively isolated and characterized by 16S rDNA sequences. Using the above-mentioned degenerate primers, seven lipase gene fragments were cloned, but not all of them could be accounted for by the clones in the library. Two full-length lipase genes obtained by TAIL-PCR were expressed in Pichia pastoris and characterized. Both were authentic lipases with optimum temperatures of ${\le}40^{\circ}C$. Our study indicates the abundant lipase diversity in glacier soil as well as the feasibility of sequence-based screening in discovering new lipase genes from complex environmental samples.

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

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.155-160
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• 2005

Abstract A direct approach was used to retrieve active lipases from Paenibacillus polymyxa genome databases. Twelve putative lipase genes were tested using a typical lipase sequence rule built on the basis of a consensus sequence of a catalytic triad and oxyanion hole. Among them, six genes satisfied the sequence rule and had similarity (about 25%) with known bacterial lipases. To obtain the six lipase proteins, lipase genes were expressed in E. coli cells and lipolytic activities were measured by using tributyrin plate and pnitrophenyl caproate. One of them, contig 160-26, was expressed as a soluble and active form in E. coli cell. After purifying on Ni-NTA column, its detailed biochemical properties were characterized. It had a maximum hydrolytic activity at $30^{\circ}C$ and pH 7- 8, and was stable up to $40^{\circ}C$ and in the range of pH 5- 8. It most rapidly hydrolyzed pNPC$_6$ among various PNPesters. The other contigs were expressed more or less as soluble forms, although no lipolytic activities were detected. As they have many conserved regions with lipase 160-26 as well as other bacterial lipases throughout their equence, they are suggested as true lipase genes.

• 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.