• KSBB Journal
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• 제19권2호
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• pp.148-153
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• 2004

활성 효모의 동물사료 첨가제로의 이용성을 증진시키기 위하여 lipase 생산성이 높은 효모를 (주)강남유지로부터 채취한 폐유와 슬러지로부터 분리하였다. 분리된 균주를 이용, 자외선 돌연변이를 통해 lipase 생산성이 높은 균주를 개발하였으며 산업용 배양배지의 선별, 배양공정의 개선에 관한 연구를 수행하였다. 산업용 배지의 탄소원으로는 고과당, 질소원으로는 CSL이 각각 선정되었으며, 2%의 고과당, 1%의 CSL에서 배양조건을 최적화시키고자 하였다. 1%의 올리브유 첨가, 접종량 4%, 초기 pH 5, 그리고 배양온도 27$^{\circ}C$에서 lipase의 생산성이 최대가 됨을 확인할 수 있었으며 이 때 lipase 역가는 1.12 U/mL를 얻을 수 있었다.

• 한국식품영양과학회지
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• 제45권4호
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• pp.533-541
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• 2016

페놀화합물의 함량이 높다고 알려진 카카오(powder)로부터 카카오 추출물(CE)을 획득한 후, CE가 pancreatic lipase의 활성에 미치는 영향과 CE를 함유한 emulsion의 aging에 의한 가수분해율 변화를 살펴보기 위하여 두 가지 형태의 기질을 사용한 pH-stat digestion model을 이용하였다. Type I 의 경우 소화액에 CE와 콩기름을 첨가하여 emulsion을 제조하였으며 aging time(0, 5, 24시간)에 따른 가수분해 변화를 살펴보았다. CE를 첨가하였을 때의 가수분해율은 CE를 첨가하지 않았을 때와 큰 차이를 보이지 않아 CE가 pancreatic lipase 활성에 영향을 주지 않았다고 판단된다. 그러나 aging time이 지남에 따라 CE를 첨가하였을 때와 CE를 첨가하지 않았을 때의 가수분해율 모두 감소하였다. 이는 CE의 영향보다는 aging time이 길어짐에 따라 emulsion의 안정도가 낮아져 지방구 크기가 증가하여 가수분해율이 모두 감소한 것으로 생각되고, 따라서 이 모델에서는 CE에 의한 가수분해 저하가 크지 않았다. 한편 type II의 경우 먼저 콩기름과 CE, Tween 20를 혼합하고 고압균질기를 사용하여 micro-emulsion을 제조한 후, 이를 기질로 하여 aging time(0, 2, 4, 7, 18, 43일)에 따른 가수분해율 변화를 살펴보았다. 그 결과 aging time에 따라 CE를 첨가하지 않은 control과 CE를 첨가한 CE-emulsion의 가수분해율이 감소하였는데, 특히 control보다 CE-emulsion이 더 많이 감소하여 43일에는 control의 ${\Phi}$ max가 92.13%(0일, 96.53%)였으나 CE-emulsion은 77.69%(0일, 97.91%)를 보이면서 CE-emulsion의 가수분해 반응이 control에 비해 낮았다. 다른 kinetic parameter(k value, $t_{1/2}$ 등)에서도 이와 유사한 경향을 나타냈다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.46-50
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• 1996

In order to design industrial scale reactors and proceises for multi-phase biocatalytic reactions, it is essential to understand the mechanisms by which such systems operate. To il-lustrate how such mechanisms can be modeled, the hydrolysis of the primary ester groups of triglycerides to produce fatty acids and monoglycerides by lipased (glycerol-ester hydrolase) catalysis has been selected as an example of multiphase biocatalysis. Lipase is specific in its behavior such that it can act only on the hydrolyzed (or emulsified) part of the substrate. This follows because the active center of the enzyme is catalytically active only when the substrate contacts it in its hydrolyzed form. In other words, lipase acts only when it can shuttleback and forth between the emulsion phase and the water phase, presumably within an interphase or boundary layer between these two phases. In industrial applications lipase is employed as a fat splitting enzyme to remove fat stains from fabrics, in making cheese, to flavor milk products, and to degrade fats in waste products. Effective use of lipase in these processes requires a fundamental understanding of its kinetic behavior and interactions with substrates under various environmental conditions. Therefore, this study focuses on modeling and simulating the enzymatic activity of the lipase as a step towards the basic understanding of multi-phase biocatalysis processes.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.282-295
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• 2005

The processing of dietary lipids can be distinguished in several sequential steps, including their emulsification, hydrolysis and micellization, before they are absorbed by the enterocytes. Emulsification of lipids starts in the stomach and is mediated by physical forces and favoured by the partial lipolysis of the dietary lipids due to the activity of gastric lipase. The process of lipid digestion continues in the duodenum where pancreatic triacylglycerol lipase (PTL) releases 50 to 70% of dietary fatty acids. Bile salts at low concentrations stimulate PTL activity, but higher concentrations inhibit PTL activity. Pancreatic triacylglycerol lipase activity is regulated by colipase, that interacts with bile salts and PTL and can release bile salt mediated PTL inhibition. Without colipase, PTL is unable to hydrolyse fatty acids from dietary triacylglycerols, resulting in fat malabsorption with severe consequences on bioavailability of dietary lipids and fat-soluble vitamins. Furthermore, carboxyl ester lipase, a pancreatic enzyme that is bile salt-stimulated and displays wide substrate reactivities, is involved in lipid digestion. The products of lipolysis are removed from the water-oil interface by incorporation into mixed micelles that are formed spontaneously by the interaction of bile salts. Monoacylglycerols and phospholipids enhance the ability of bile salts to form mixed micelles. Formation of mixed micelles is necessary to move the non-polar lipids across the unstirred water layer adjacent to the mucosal cells, thereby facilitating absorption.

• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1655-1660
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• 2007

A metagenome is a unique resource to search for novel microbial enzymes from the unculturable microorganisms in soil. A forest soil metagenomic library using a fosmid and soil microbial DNA from Gwangneung forest, Korea, was constructed in Escherichia coli and screened to select lipolytic genes. A total of seven unique lipolytic clones were selected by screening of the 31,000-member forest soil metagenome library based on tributyrin hydrolysis. The ORFs for lipolytic activity were subcloned in a high copy number plasmid by screening the secondary shortgun libraries from the seven clones. Since the lipolytic enzymes were well secreted in E. coli into the culture broth, the lipolytic activity of the subclones was confirmed by the hydrolysis of p-nitrophenyl butyrate using culture supernatant. Deduced amino acid sequence analysis of the identified ORFs for lipolytic activity revealed that 4 genes encode hormone-sensitive lipase (HSL) in lipase family IV. Phylogenetic analysis indicated that 4 proteins were clustered with HSL in the database and other metagenomic HSLs. The other 2 genes and 1 gene encode non-heme peroxidase-like enzymes of lipase family V and a GDSL family esterase/lipase in family II, respectively. The gene for the GDSL enzyme is the first description of the enzyme from metagenomic screening.

• Journal of Animal Science and Technology
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• 제55권4호
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• pp.303-314
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• 2013

Knowledge regarding lipid catabolism has been of great interest in the field of animal sciences. In the livestock industry, excess fat accretion in meat is costly to the producer and undesirable to the consumer. However, intramuscular fat (marbling) is desirable to enhance carcass and product quality. The manipulation of lipid content to meet the goals of animal production requires an understanding of the detailed mechanisms of lipid catabolism to help meticulously design nutritional, pharmacological, and physiological approaches to regulate fat accretion. The concept of a basic system of lipases and their co-regulators has been identified. The major lipases cleave triacylglycerol (TAG) stored in lipid droplets in a sequential manner. In adipose tissue, adipose triglyceride lipase (ATGL) performs the first and rate-limiting step of TAG breakdown through hydrolysis at the sn-1 position of TAG to release a non-esterified fatty acid (NEFA) and diacylglycerol (DAG). Subsequently, cleavage of DAG occurs via the rate-limiting enzyme hormone-sensitive lipase (HSL) for DAG catabolism, which is followed by monoglyceride lipase (MGL) for monoacylglycerol (MAG) hydrolysis. Recent identification of the co-activator (Comparative Gene Identification-58) and inhibitor [G(0)/G(1) Switch Gene 2] of ATGL have helped elucidate this important initial step of TAG breakdown, while also generating more questions. Additionally, the roles of these lipolysis-related enzymes in muscle, liver and skin tissue have also been found to be of great importance for the investigation of systemic lipolytic regulation.

• 한국식품영양과학회지
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• 제3권1호
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• pp.23-28
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• 1974

Fatty acids of Gingko biloba lipid and its binding position were determined by using pancreatic lipase. Optimum conditions for hydrolysis of glyceride were found as 9mg of lipase and 5 min reaction time for 50 mg of TG. The results showed that oleic acid and linoleic acid were presented about 40% and 29.7%, respectively, but linoleic acid was very small comparing with other seeds. It was found that both saturated and unsaturated fatty acids were almost equally distributed at ${\beta}\;and\;{\alpha}{\cdot}{\alpha}'-position$ of TG.

• 한국응용과학기술학회지
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• 제2권2호
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• pp.11-14
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• 1985

• Bulletin of the Korean Chemical Society
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• 제22권4호
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• pp.427-428
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• 2001

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.25-30
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• 2002

A lipase of Staphylococcus aureus B56 was purified from a culture supernatant and its molecular weight was estimated to be 45 kDa by SDS-PAGE. The optimum temperature and pH for the hydrolysis of olive oil was $42^{\circ}C$ and pH 8-8.5, respectively. The enzyme was stable up to $55^{\circ}C$ in the presence of $Ca^++$ at pHs 5-11. The lipase gene was cloned using the PCR amplification method. The sequence analysis showed an open reading frame of 2,076 bp, which encoded a preproenzyme of 691 amino acids. The preproenzyme was composed of a signal sequence (37 aa), propeptide (255 aa), and mature enzyme (399 aa). Based on a sequence comparison, lipase B56 constituted of a separate subgroup among the staphylococcal lipase groups, such as S. aureus PS54 and S. haemolyticus L62 lipases, and was distinct from other lipases in their optimum pH and substrate specificity.