• Polymer(Korea)
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• v.31 no.1
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• pp.20-24
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• 2007

The preservation of biological activity of protein drugs in formulation is still a major challenge for successful drug delivery. Lipase was encapsulated in poly (D,L-lactide- co-glycolide) PLGA nano-particles using a w/o/w solvent evaporation technique. The lipase-containing PLGA/poly (vinyl alcohol) (PVA) nanoparticles were characterized with regard to morphology, size, size distribution, lipase-loading efficiency, in vitro lipase release, and stability of lipase activity. The size of nanoparticles increased as polymer concentration was increased. The size of particles was not significantly affected by the PVA concentration; on the other hand, the particle size distribution was the narrowest when 4% of PVA was used. In optimum conditions, we possessed nanoparticles that characterized 72.5% of encapsulation efficiency, $198.3{\pm}13.8 nm$ size diameter. During the initial burst phase, the in vitro release rate was very fast, reaching 83% within 12 days. Until days 6, enzyme activity increased as the amount of lipase released was increased.

• Analytical Science and Technology
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• v.29 no.3
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• pp.105-113
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• 2016

The present study investigated the immobilization of lipases on silica nanoparticles and silica-coated magnetite nanoparticles as supports with a functional group to enhance the stability of lipase. The influence of functional groups, such as the epoxy group and the amine group, on the activity and stability of immobilized lipase was also studied. The epoxy group and the amino group were introduced onto the surface of nanoparticles by glycidyl methacrylate and aminopropyl triethoxysilane, respectively. Immobilized Candida rugosa lipase on silica nanoparticles and silica-coated magnetite nanoparticles with a functional group showed slightly lower initial enzyme activities than free enzyme; however, the immobilized Candida rugosa lipase retained over 92 % of the initial activity, even after 3 times reuse. Lipase was also immobilized on the silica-coated magnetite nanoparticles by cross-linked enzyme aggregate (CLEA) using glutaraldehyde and covalent binding, respectively, were also studied. Immobilized Candida rugosa lipase on silica nanoparticles and silica-coated magnetite nanoparticles by CLEA and covalent binding showed higher enzyme activities than free enzyme, while immobilized Candida rugosa lipase retained over 73 % of the initial activity after 5 times reuse.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.969-974
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• 2011

This study was performed to investigate the inhibitory activity of Ecklonia cava (EC) against lipase and the stability of this activity under various heat and pH conditions. As a result, EC ethanol extract showed lipase inhibitory activity of 59, 34 and 19% at concentrations of 5, 2.5 and 1 mg/mL, whereas the water extract showed low inhibitory activity at all concentrations compared to that of the ethanol extracts. In a heat and pH stability test, the inhibitory activity of the EC ethanol extract increased with heat treatment at $121^{\circ}C$ for 15 min compared with the control and was stable in the pH range of 2~10. Therefore, the EC ethanol extract could be useful as a natural anti-obesity agent.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1827-1834
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• 2015

The SMG1 lipase from Malassezia globosa is a newly found mono- and diacylglycerol (DAG) lipase that has a unique lid in the loop conformation that differs from the common alpha-helix lid. In the present study, we characterized the contribution of three residues, L103 and F104 in the lid and F278 in the rim of the binding site groove, on the function of SMG1 lipase. Site-directed mutagenesis was conducted at these sites, and each of the mutants was expressed in the yeast Pichia pastoris, purified, and characterized for their activity toward DAG and p-nitrophenol (pNP) ester. Compared with wild-type SMG1, F278A retained approximately 78% of its activity toward DAG, but only 11% activity toward pNP octanoate (pNP-C8). L103G increased its activity on pNP-C8 by approximately 2-fold, whereas F104G showed an approximate 40% decrease in pNP-C8 activity, and they both showed decreased activity on the DAG emulsion. The deletion of 103-104 retained approximately 30% of its activity toward the DAG emulsion, with an almost complete loss of pNP-C8 activity. The deletion of 103-104 showed a weaker penetration ability to a soybean phosphocholine monolayer than wild-type SMG1. Based on the modulation of the specificity and activity observed, a pNP-C8 binding model for the ester (pNP-C8, N102, and F278 form a flexible bridge) and a specific lipid-anchoring mechanism for DAG (L103 and F104 serve as "anchors" to the lipid interface) were proposed.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1067-1076
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• 2016

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30℃ and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0℃ and good stability at temperatures below 35℃. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30℃. Its activity was slightly affected by some metal ions such as K⁺, Ca²⁺, and Na⁺. The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.661-667
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• 2013

Lipase-producing bacterial strains were isolated from Antarctic soil samples using the tricaprylin agar plate method. Seven strains with relatively strong lipase activities were selected. All of them turned out to be Bacillus pumilus strains by the 16S rRNA gene sequence analysis. Their corresponding lipase genes were cloned, sequenced, and compared. Finally, three different Bacillus pumilus lipases (BPL1, BPL2, and BPL3) were chosen. Their amino acid sequence identities were in the range of 92-98% with the previous Bacillus pumilus lipases. Their optimum temperatures and pHs were measured to be $40^{\circ}C$ and pH 9. Lipase BPL1 and lipase BPL2 were stable up to $30^{\circ}C$, whereas lipase BPL3 was stable up to $20^{\circ}C$. Lipase BPL2 was stable within a pH range of 6-10, whereas lipase BPL1 and lipase BPL3 were stable within a pH range of 5-11, showing strong alkaline tolerance. All these lipases exhibited high hydrolytic activity toward p-nitrophenyl caprylate ($C_8$). In addition, lipase BPL1 showed high hydrolytic activity toward tributyrin, whereas lipase BPL2 and lipase BPL3 hydrolyzed tricaprylin and castor oil preferentially. These results demonstrated that the three Antarctic Bacillus lipases were alkaliphilic and had a substrate preference toward short- and medium-chain triglycerides. These Antarctic Bacillus lipases might be used in detergent and food industries.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.84-91
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• 2012

Two staphylococcal lipases were obtained from Staphylococcus epidermidis S2 and Staphylococcus aureus S11 isolated from sebaceous areas on the skin of the human face. The molecular mass of both enzymes was estimated to be 45 kDa by SDS-PAGE. S2 lipase displayed its highest activity in the hydrolysis of olive oil at $32^{\circ}C$ and pH 8, whereas S11 lipase showed optimal activity at $31^{\circ}C$ and pH 8.5. The S2 lipase showed the property of cold-adaptation, with activation energy of 6.52 kcal/mol. In contrast, S11 lipase's activation energy, at 21 kcal/mol, was more characteristic of mesophilic lipases. S2 lipase was stable up to $45^{\circ}C$ and within the pH range from 5 to 9, whereas S11 lipase was stable up to $50^{\circ}C$ and from pH 6 to 10. Both enzymes had high activity against tributyrin, waste soybean oil, and fish oil. Sequence analysis of the S2 lipase gene showed an open reading frame of 2,067 bp encoding a signal peptide (35 aa), a pro-peptide (267 aa), and a mature enzyme (386 aa); the S11 lipase gene, at 2,076 bp, also encoded a signal peptide (37 aa), pro-peptide (255 aa), and mature enzyme (399 aa). The two enzymes maintained amino acid sequence identity of 98-99% with other similar staphylococcal lipases. Their microbial origins and biochemical properties may make these staphylococcal lipases isolated from facial sebaceous skin suitable for use as catalysts in the cosmetic, medicinal, food, or detergent industries.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.105-110
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• 1999

Acetobacter sp. were isolated from persimmon vinegar. We studied about conditions of Aloe vinegar fermentation by an isolated strain and inhibitory effect against lipase activity. Strains DS-118 was strictly aerobic, motile, gram negative, non-spore-forming and short rod shaped. It reacted positively in catalase test, was oxidase test negative, was ureas negative, was produced acetic acid from alcohol. On the basis of these results, it was identified as a strain of Acetobacter sp. In the preparation of Aloe vinegar, optimun initial alcohol concentration, acidity, and fermentation temperature were 10%, $3{\sim}4%$ and $25^{\circ}C$, respectively. The major organic acid in Aloe vinegar was acetic acid (12%), but malic acid and ${\delta}-galactronic$ acid were also present in trace. The Aloe vinegar(acidity : 12%) inhibited lipase activity and it's $IC_{50}$ was 43%.

• 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.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1087-1097
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• 2016

An intracellular lipase from Anoxybacillus flavithermus HBB 134 was purified to 7.4-fold. The molecular mass of the enzyme was found to be about 64 kDa. The maximum activity of the enzyme was at pH 9.0 and 50℃. The enzyme was stable between pH 6.0 and 11.0 at 25℃, 40℃, and 50℃ for 24 h. The K_m and V_max of the enzyme for pNPL substrate were determined as 0.084 mM and 500 U/mg, respectively. Glycerol, sorbitol, and mannitol enhanced the enzyme thermostability. The enzyme was found to be highly stable against acetone, ethyl acetate, and diethyl ether. The presence of PMSF, NBS, DTT and β-mercaptoethanol inhibited the enzyme activity. Hg²⁺, Fe³⁺, Pb²⁺, Al³⁺, and Zn²⁺ strongly inhibited the enzyme whereas Li⁺, Na⁺, K⁺, and NH₄⁺ slightly activated it. At least 60% of the enzyme activity and stability were retained against sodium deoxycholate, sodium taurocholate, n-octyl-β-D-glucopyranoside, and CHAPS. The presence of 1% Triton X-100 caused about 34% increase in the enzyme activity. The enzyme is thought to be a true lipase since it has preferred the long-chain triacylglycerols. The lipase of HBB 134 cleaved triolein at the 1- or 3-position.