• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.187-193
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• 2009

A metagenomic library of surface-water microbes from the Yangtze River in China was constructed, and a novel esterase, designated as EstY, was isolated and characterized. EstY had 423 amino acids with an estimated molecular mass of 44 kDa and pI of 7.28. It hydrolyzed various p-nitrophenyl esters(acetate, butyrate, caprate, caprylate, laurate, myristate, and palmitate) and its best substrate was p-nitrophenyl caprate(C8). The optimum pH for EstY activity was 9.0 and the optimum temperature was $50^{\circ}C$. Metal ions, such as $Mn^{2+},\;Co^{2+},\;Hg^{2+},\;Zn^{2+},\;and\;Fe^{3+}$, strongly inhibited the activity of EstY, whereas $Mg^{2+}$ was required for maximal activity. Activity remained in the presence of 10% alcohol, acetone, isopropanol, and dimethyl sulfoxide, respectively. An analysis of the amino acid sequence deduced from estY revealed that it had 7 closely related lipolytic enzymes. Moreover, a sequence analysis showed that EstY, like its 7 relatives, did not belong to any known lipolytic enzyme family.

• Korean Journal of Veterinary Service
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• v.40 no.4
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• pp.259-264
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• 2017

In this study, the changes of low molecular weight compounds during natural decay process for 4 weeks were analyzed. Natural corruptions were observed in the slate warehouse with summer humidity and temperature throughout the rainy season by using commercially available compound feeds. Koiganal was detected from 14 days of natural decay and corruption with chicken, pig, and Korean cattle feed. Ethyl palmitate, Ethyl pentadecanoate and, Methyl elaidatel were detected from chicken, pig, and Korean cattle feed. So, Koiganal can be useful for monitoring the degree of pollution of corruption of livestock feeds in advance.

• Journal of Plant Biotechnology
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• v.46 no.4
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• pp.282-290
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• 2019

Cuphea viscosissima plants accumulate medium-chain fatty acids (MCFAs), i.e., those containing 8 ~ 14 carbons, in their seeds, in addition to the longer carbon chain fatty acids (≥16 carbons) found in a variety of plant species. Previous studies have reported the existence of three C. viscosissima MCFA-producing acyl-acyl carrier protein (ACP) thioesterases with different substrate specificities. In this study, CvFatB4, a novel cDNA clone encoding an acyl-ACP thioesterase (EC 3.1.2.14), was isolated from developing C. viscosissima seeds. Sequence alignment of the deduced amino acid sequence revealed that four catalytic residues for thioesterase activity are conserved and a putative N-terminal chloroplast transit peptide is present. Overexpression of CvFatB4 cDNA, which was under the control of the cauliflower mosaic virus 35S promoter, in Arabidopsis thaliana led to an increase in 16:0 fatty acid (palmitate) levels in the seed oil at the expense of 18:1 and other non-MCFAs.

• BMB Reports
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• v.29 no.5
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• pp.436-441
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• 1996

The palmitoyl acyl carrier protein (ACP) specific thioesterase (EC 3.1.2.14) from Iris pseudoacorus was purified and characterized. The thioesterase which was very unstable in relatively high salt concentrations was eluted using a co-gradient of Triton X-100 and low concentration of KCl or Na-phosphate from Q-Sepharose, DEAE-Sepharose, and hydroxyapatite chromatography. SDS-PAGE analysis showed a single band with a molecular weight of 35,000. The native molecular weight of approximately 37,000 was estimated by Sephacryl S-200 chromatography, indicating that the enzyme is a monomer. The thioesterase activity was inhibited about 75% and 50% by N-ethylmaleimide (2 mM) and phenylmethylsulfonyl fluoride (2 mM). respectively. The N-ethylmaleimide-inactivation was protected by sodium palmitate but the inactivation with phenylmethylsulfonyl fluoride was not protected. Oxidation of thiols by 2 mM 5.5'-dithio-bis-(2-nitrobenzoic acid) resulted in 65% inactivation of the enzyme. These results suggest that a cysteinyl residue is essential to the catalytic reaction of the enzyme. The enzyme activity was increased by sodium citrate and also by $Cu^{2+}$

• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.49-57
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• 1982

Transesterification reactions were carried out with myo-inositol and five fatty acid methyl esters such as methyl laurate, methyl myristate, methyl palmitate, methyl stearate and methyl oleate in the dimethylsulfoxide solvent. Their products were separated by both thin layer chromatography and column chromatography, and myo-inositol monoesters were quantitatively separated by counter current distribution. We measured their surface tension, foaming power and emulsifying power, determined critical micelle concentrations by the color method, and evaluated their hydrophilic-lipophilic balance. The results show that myo-inositol monoesters exhibit surface activites.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.335-340
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• 1995

Two types of Rhizoctonia solani esterases induced by cutin hydrolysate were partially purified by ammonium sulfate precipitation and gel filtration. The esterase I with hydrolyzing activity toward both ${\rho}-ni-trophenyl$ butyrate and ${\rho}-nitrophenyl$ palmitate and the esterase II with hydrolyzing activity toward only ${\rho}-ni-trophenyl$ butyrate were inhibited by ebelactone B, an esterase inhibitor produced by actinomycetes with $IC_{50}$ values of 0.01 and $0.09{\;}\mu\textrm{g}/l$, respectively. Spraying on rice seedling with ebelactone B at a concentration of $30{\;}\mu\textrm{g}/ml$ completely suppressed infection by R. solani. Ebelactone B could not protect the wounded rice seedling and did not show any inhibitory effect on the mycelial growth at a concentration of 1 mg/ml. These results indicate that ebelactone B, an esterase inhibitor protects rice plants from infection with R. solani by inhibition of penetration, not through fungitoxic or fungicidal effect.

• Journal of Microbiology
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• v.41 no.2
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• pp.95-101
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• 2003

The lipase gene (lipA) and its activator gene (lipB) of Pseudomonas sp. SW-3 were cloned and sequenced. The lipB was found to be present immediately downstream of lipA. The deduced amino acid sequences of lipA and lipB showed a high level of homology to those of other lipases belonging to the family I.1 of bacterial lipases. When lipA was expressed in Escherichia coli using T7 promoter, an active lipase was produced in cells carrying both lipA and lipB, but not in cells harboring only lipA. Recombinant lipase (rPSL) overproduced in an insoluble form was solubilized in the presence of 8 M urea, purified in a urea-denatured form and refolded by removing urea in the presence of the Ca$\^$2+/ ion. rPLS had maximum activity at pH 8.0 and 50$^{\circ}C$, was stable at pHs from 7.0 to 9.0 and below 50$^{\circ}C$, and showed the highest activity toward the p-nitrophenyl ester of palmitate (Cl6).

• Food Science and Preservation
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• v.7 no.1
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• pp.117-123
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• 2000

In order to promote the utilization of Hovenia dulcis leaf as food, leaf tea was nanufactured and its physicochemical properties were examined. Aong proximate composiotns of Hovenia dulcis leaf tea were found in both fermented tea and roasted tea the higher contents of total sugar and crude protein. In minerals component of fermented tea and roasted tea, potassium (K) was the most high amounts of 11,560.6 ppm and 11,084.6 ppm, respectively. The highest contents of free sugar in both teas were mainly consisted of sucrose, the amounts of sucrose showed 1.47% and 1.94% . In case of organic acids, oxalic acid and citric acid were revealed 631.26mg% and 660.05mg%, respectively. The highest contents of total amino acid in fermented tea and roasted tea were 812.01mg% and 709.72mg% of glutamic acid. the fatty acids of fermented tea and roasted tea were mainly composed of 40.18% of linolenic acid and 26.92% of palmitic acid, respectively. The major volatile compounds of fermented tea and roasted tea were composed of 3, 7, 11, 15-tertramethyl-2-hexadecen-1-ol and methyl palmitate and the amounts of those showed 290.1ppm and 472.97 ppm, respectively. The tannins of fermented tea and roasted tea were 1.02% and 1.26% , as the extraction steps increased the tannin contents decreased. In Hunter's color values of tea extract L and b values decreased , while a value of those increased as the extraction steps were repeated.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.21-27
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• 2012

Ground seawater in the east area of the volcanic Jeju Island contains abundant minerals. We investigated the metabolic activity of electrodialyzed, desalted ground seawater (EDSW) from Jeju in both cultured cells and animals. The addition of EDSW to the culture medium (up to 20%, v/v) reduced the leakage of lactate dehydrogenase and increased MTT activity in CHO-IR cells. EDSW (10%) promoted insulin-induced glucose consumption in L6 muscle cells as well as the activities of the liver ethanol-metabolizing enzymes, alcohol dehydrogenase and aldehyde dehydrogenase. Moreover, EDSW suppressed palmitate-induced intracellular fat accumulation in human hepatoma $HepG_2$ cells. Activities of AMP-stimulated protein kinase and acetyl CoA carboxylase, enzymes that modulate fat metabolism, were altered by EDSW in $HepG_2$ cells toward the suppression of intracellular lipid accumulation. EDSW also suppressed hepatic fat accumulation induced by a high-fat diet in mice. Taken together, EDSW showed beneficial metabolic effects, including the enhancement of ethanol metabolism and insulin-induced glucose consumption, and the suppression of intrahepatic fat accumulation.

• Journal of Ginseng Research
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• v.24 no.2
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• pp.64-67
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• 2000

This study was carried out to investigate the possible determination of total phenolic compounds by Folin-Denis method from Panax ginseng C.A. Meyer and their extraction conditions. It was possible to apply the method for determination of total phenolic compounds from Korean red ginseng. But 3 kinds of amino acids such as tyrosine, cystein and tryptophan, and 3 kinds of vitamins such as ascorbic acid, pyridoxin HCI and thiamine HCI affected strongly the colorization by the method. Effective alcoholic solvent for the extraction was 60% ethanol, appropriate extraction temperature, time and times were 40-80。C, 1-2 hours and 3 times, respectively.