• Journal of Microbiology and Biotechnology
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• 제17권4호
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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.

• 한국식품영양과학회지
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• 제20권1호
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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.

• Journal of Microbiology and Biotechnology
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• 제10권5호
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• pp.656-662
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• 2000

A high level of Staphylococcus haemolyticus L62 lipase was expressed in an Escherichia coli transformant. The expressed lipase activity in the cell-free extract was 70,800 U/l, which corresponded to 30% of the total cellular protein. Pre-mixing of the l62 lipase with some nonionic detergents enhanced its hydrolytic activity towards olive oil: Tween detergents activated the L62 lipase by 3 fold. Gel filtration chromatography of the Tween-80-L62 lipase mixture demonstrated a polymerized complex (∼180 kDa) formed exclusively between Tween-80 and the L62 lipase. The lipase enzyme in the complex showed a higher specific activity towards most triacylglycerols than the intact L62 lipase. The activity enhancement towards each substrate was quite different depending on the acyl chain length; the activity towards tributyrin, trilinolein, and trilinolenin was much more enhanced than the towards the medium and the long-chain saturated triglycerides.

• 한국축산식품학회지
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• 제20권2호
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• pp.101-106
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• 2000

유지방구로부터 분리 정제한 lipase의 활성과 안정성에 미치는 pH의 영향을 야자유와 균질유를 기질로 하여 조사하였다. 효소원으로 buttermilk를 사용하였을 경우는 반응온도 $37^{\circ}C$에서 야자유, 균질유 모두 pH 9.5에서 최대 활성을 나타내었으며, 전형적인 종형의 pH의 존곡선을 나타내었다. 그러나 반응온도 $0^{\circ}C$에서는 pH 10.0까지 활성이 증가하였다. 정제 lipase를 사용한 경우는 반응응도 $37^{\circ}C$에서 균질유를 기질로 사용하였을 때 종 모양의 곡선을 나타내었으며, 최대 활성은 pH 9.0에서 나타났다. 반응온도 $0^{\circ}C$에서는 pH 10.0까지 활성이 계속 증가하였다. BSA를 첨가한 야자유를 기질로 사용한 경우는 반응온도 $37^{\circ}C$, $0^{\circ}C$ 모두 최대 활성이 pH 9.5에 나타났으며, pH 10.0에서는 활성이 현저하게 저하하였다. 정제 lipase의 안정성에 미치는 pH의 증가에 따라 현저하게 저하하였다. pH 10.0에서 $37^{\circ}C$로 20분간 효소를 유지하였을 경우 lipase의 활성은 pH 8.5 때의 활성에 비하여 13%로 감소하였다. 그러나, $4^{\circ}C$에서 60분간 효소를 유지하였을 경우는 lipase 활성이 pH 7.5∼10.0의 범위에서 안정하였다.

• Journal of Microbiology
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• 제41권1호
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• pp.22-27
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• 2003

A lipase from Aeromonas sp. LPB 4, a psychrotophile isolated from a sea sediment was purified and characterized. The lipase was purified 53.5 fold to a homogeneous state by acetone precipitation and QAE sephadex column chromatography and its molecular weight was determined to be 50 kDa by SDS-PAGE. The enzyme exhibited maximum activity at 10$^{\circ}C$ and was stable at temperatures lower than 50$^{\circ}C$. This lipase favored substrates containing medium carbon chain of acyl group, while too low and high carbon chain decreased its activity. The lipolytic activity of purified lipase was slightly increased by the addition of 0.1% detergent, but decreased by 1% of detergent. Butanol severely decreased the lipase activity while methanol increased the activity about 15%.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.845-855
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• 2015

The present study describes the gene cloning and high-level expression of an alkaline and thermostable lipase gene from Trichosporon coremiiforme V3. Nucleotide analysis revealed that this lipase gene has an open reading frame of 1,692 bp without any introns, encoding a protein of 563 amino acid residues. The lipase gene without its signal sequence was cloned into plasmid pPICZαA and overexpressed in Pichia pastoris X33. The maximum lipase activity of recombinant lipase was 5,000 U/ml, which was obtained in fed-batch cultivation after 168 h induction with methanol in a 50 L bioreactor. The purified lipase showed high temperature tolerance, and being stable at 60℃ and kept 45% enzyme activity after 1 h incubation at 70℃. The stability, effects of metal ions and other reagents were also determined. The chain length specificity of the recombinant lipase showed high activity toward triolein (C18:1) and tripalmitin (C16:0).

• 농업과학연구
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• 제40권3호
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• pp.227-235
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• 2013

This study was conducted to prove the effect of irradiation on lipases (lipase AK, lipase AH, lipase PS-D, Lipozyme TLIM, Lipozyme RMIM and Novozyme SP435) which were used for interesterification reaction using batch type reactor. Through such interesterification, structured lipid (1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl, POS) was synthesized by lipase treated with irradiation at different doses (0, 3, 7, 14, 29 and 59 kGy) using canola oil, palmitic ethyl ester (PEE) and stearic ethyl ester (StEE). After the reaction, fatty acid composition of triacylglycerol (TAG) in structured lipid was analyzed to compare the lipase activity. The results showed that activity of the irradiated lipase AH, PS-D and Novozyme SP435 with certain dose (3 kGy) were slightly improved. Such change of lipase activity suggested that irradiation might affect on the interesterification properties. Especially, Lipase AK, Lipozyme TLIM and Lipozyme RMIM after at 3 kGy irradiation showed that content of stearic acid ($C_{18:0}$) was increased while palmitic acid ($C_{16:0}$) decreased in the interesterified products.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.329-333
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• 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.

• 한국축산식품학회지
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• 제40권1호
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• pp.87-95
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• 2020

In this study, we separated and purified lipase inhibitory peptide from fermented milk by Lactobacillus plantarum Q180 with the aim of developing a new functional anti-lipase activity yogurt product. L. plantarum 180 was inoculated into 10% reconstituted skimmed milk and incubated at 37℃ until the pH of the culture reached pH 4.4. The lipase activity was measured using porcine pancreatic lipase. The lipase inhibitory peptides were gradually isolated by ultrafiltration, reversed phase column chromatography (RPC), reversed phase high-performance liquid chromatography (RP-HPLC), and gel permeation high-performance liquid chromatography (GP-HPLC) from the fermented milk by L. plantarum Q180. An ODS-AQ column was used for the RPC, a Vydac C18 column for the RP-HPLC, and a Superdex Peptide HR column for the GP-HPLC. The peptide was composed of Asp, Thr, Ile, Ser, Ala, and Gln, and the anti-lipase activity (IC₅₀) was 2,817 ㎍/mL.

• Journal of Microbiology and Biotechnology
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• 제7권2호
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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.