• 생명과학회지
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• 제26권5호
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• pp.603-607
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• 2016

유기용매 내성 세균 Pseudomonas sp. BCNU 106으로부터 생산된 리파아제 조효소액은 pH 4-10의 넓은 범위의 pH와 37℃에서 매우 안정적이었다. BCNU 106의 리파아제 안정성은 25% xylene, hexane, octane, toluene, chloroform 및 dodecane에서 증가하였으며, 상업적인 고정화 효소와 비교해도 우수한 안정성을 보이고 있다. 그리고 Cu²⁺, Hg²⁺, Zn²⁺ 및 Mn²⁺ 존재 하에서 110% 이상의 상대활성을 나타낸 반면에, Fe²⁺에서는 효소활성이 억제되었다. 게다가 계면활성제인 tween 80과 triton X-100 및 SDS에서도 높은 안정성을 유지됨이 확인되었다. 본 연구에서 유기용매 내성 Pseudomonas sp. BCNU 106의 리파아제는 고정화 효소에 못지않은 효소 활성 및 안정성을 유지함이 밝혀져 다양한 산업공정에서 잠재적인 생물촉매로 적용될 수 있는 가능성을 확인할 수 있었다.

• Journal of Ginseng Research
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• 제14권2호
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• pp.157-161
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• 1990

We have been isolating various physiologically active substances from non-saponin fraction of Korean Red Ginseng. These are adenosine, pyre-glutamic acid, dencichine and acidic polysaccharide. Adenosine and pyre-glutamic acid are known to inhibit epinephrine-induced lipolysis in fat cells and stimulate the insulin-mediated lipogenesis. In addition to these actions, adenosine was found to inhibit both norepinephrine- and histamine-induced aorta constriction, and pyre·glutamic acid inhibits angiotensin-converting enzyme. Dencichine stimulated histamine-induced aorta constriction. Finally, acidic polysaccharide was found to inhibit both lipolytic and anorexigenic actions of Toxohormone-L. Based on these experimental results, I presented a briefreview on these compounds isolated from non-saponin fraction of Korea Red Ginseng.

• Asian-Australasian Journal of Animal Sciences
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• 제29권11호
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• pp.1593-1600
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• 2016

This research was conducted to investigate the physiological consequences of undernourished yak. Twelve Maiwa yak ($110.3{\pm}5.85kg$) were randomly divided into two groups (baseline and starvation group). The yak of baseline group were slaughtered at day 0, while the other group of yak were kept in shed without feed but allowed free access to water, salt and free movement for 9 days. Blood samples of the starvation group were collected on day 0, 1, 2, 3, 5, 7, 9 and the starved yak were slaughtered after the final blood sample collection. The liver and muscle glycogen of the starvation group decreased (p<0.01), and the lipid content also decreased while the content of moisture and ash increased (p<0.05) both in Longissimus dorsi and liver compared with the baseline group. The plasma insulin and glucose of the starved yak decreased at first and then kept stable but at a relatively lower level during the following days (p<0.01). On the contrary, the non-esterified fatty acids was increased (p<0.01). Beyond our expectation, the ketone bodies of ${\beta}$-hydroxybutyric acid and acetoacetic acid decreased with prolonged starvation (p<0.01). Furthermore, the mRNA expression of lipogenetic enzyme fatty acid synthase and lipoprotein lipase in subcutaneous adipose tissue of starved yak were down-regulated (p<0.01), whereas the mRNA expression of lipolytic enzyme carnitine palmitoyltransferase-1 and hormone sensitive lipase were up-regulated (p<0.01) after 9 days of starvation. The phosphoenolpyruvate carboxykinase and pyruvate carboxylase, responsible for hepatic gluconeogenesis were up-regulated (p<0.01). It was concluded that yak derive energy by gluconeogenesis promotion and fat storage mobilization during starvation but without ketone body accumulation in the plasma.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.277-288
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• 2017

Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p-Nitrophenyl palmitate (pNPP) hydrolysis was maximal at $40^{\circ}C$ and pH 7.0 for the R. miehei lipase, and at $30^{\circ}C$ and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to pNPP, but the $V_{max}$ of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM $Hg^{2+}$, $Zn^{2+}$, or $Mn^{2+}$, 10 mM N-bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n-hexane, cyclohexane, n-heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the pNPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p-nitrophenyl (pNP) esters with C8-C16 acids, exhibiting maximum activity towards pNP-caprylate (R. miehei) and pNP-dodecanoate (Rh. oryzae). The purified lipases are promising candidates for various biotechnological applications.

• Journal of Nutrition and Health
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• 제30권4호
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• pp.386-393
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• 1997

This experiment was performed to investigate the effect of different dietary lipids on the risk factors of coronary vascular disease(CVD) in ovariectomized rats. female rats of Sprague-Dawley stram were divided into sham-operated(sham) and ovariectomized(ovx) groups and then each group was divided into a beef fallow group, a soy bean oil group and a fish oil group. After 16 weeks of feeding on experimental diets, animals were sacrificed and blood, liver, kidney and perirenal fat pad were obtained. Food intake and weight gain of fish oil group were significantly lower than other dietary lipid groups. food intake and weight gain tended to be higher in ovx groups than in sham groups. The weight Index(g/100g body weight) of liver and kidney was higher in the fish oil group than the other groups and weight index was lower in ovx groups compared to sham groups. The weight of the perirenal fat pad was the highest in the beef tallow group and the lowest in the fish oil group. The fish oil group showed the lowest total cholesterol(TC) and triglyceride (TG) levels in serum. Serum TG levels were lower in all ovx groups than in sham groups, but serum TC levels were not influenced by ovariectomy. fatty acid composition of serum reflects the recent dietary Intake of fat. Linoleic acid content was tile highest in soy bean oil group and eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) contents were the highest in fish oil group. fatty acid composition of adipose tissue, especially EPA and DHA contents in perirenal fat pad, was highest in the fish oil group. Saturated fatty acid(SFA) and monounsaturated fatty acid(MUFA) in serum and adipose tissue did not reflect fatty acid intake. The activities of glucose-6-phosphate dehydrogenase, a lipogenic enzyme, in the blood of the beef tallow and soybean oil groups showed the tendency to be high and that of the fish oil group to be low in ovx. Carnitine acetyltransferase, a lipolytic enzyme, showed the highest activity in the liver of the fish oil group and was least active in the soy bean oil group.

• 한국식품과학회지
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• 제8권1호
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• pp.33-41
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• 1976

1. 유기질소원(有機窒素源)으로는 soybean meal, 무기질소원(無機窒素源)으로는 $(NH_4)_2SO_4$가 lipase생산(生産)에 가장 효과(效果)이었다. 2. 배양중(培養中) 배지(培地)의 pH저하(低下)를 이르키는 xylose, glucose, fructose, galactose, mannose, maltose, soluble starch, dextrin을 탄소원(炭素源)으로 첨가(添加)하였을 때 lipase 생산(生産)이 심(甚)하게 저해(沮害)되었다. sucrose는 lipase생산(生産)을 저해(沮害)하지 않았으나 첨가효과(添加效果)는 인정(認定)되지 않았다. 3. 인산염(燐酸鹽)으로서는 $K_2HPO_4$, 마그네슘염(鹽)으로서는 $MgSO_4{\cdot}7H_2O$가 lipase생산(生産)에 가장 효과적(效果的)이었다. 4. Olive유(油), 대두유(大豆油) 및 야자유(油)의 첨가(添加)는 lipase생산(生産)을 증가(增加)시켰으며 1% olive유(油) 첨가시(添加時) lipase생산(生産)이 50% 증가(增加)되었다. 5. yeast extract $0.05{\sim}0.07%$첨가시(添加時) lipase생산(生産)이 약간 증가(增加)되었다. 6. 본균(本菌)의 lipase생산(生産)에 가장 적합(適合)한 배지(培地)는 soybean meal 2%, $K_2HPO_4$ 0.5%, $(NH_4)_2SO_4$ 0.1%, $MgSO_4{\cdot}7H_2O$ 0.05%, yeast extract 0.05%, olive유(油) 1%의 조성(組成)의 것으로서 최적배양조건하(最適培養條件下)에서 48시간(時間) 배양시(培養時)에 lipase생산(生産)이 최고(最高)에 도달(到達)하였다.

• 한국균학회지
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• 제30권2호
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• pp.147-151
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• 2002

Trichoderma속 균주는 느타리버섯 재배 시 발생되는 버섯 푸른곰팡이병의 주요 원인균이다. 후발효된 버섯 배지로부터 버섯 푸른곰팡이병균에 항균활성을 나타내는 길항세균(KATB 99121, KATB 99122 및 KATB 99123)을 분리하였다. 분리세균 중 KATB 99121은 T. harzianum(4균주). T. viride 및 T. hamatum과 동물병원성 곰팡이 Candida albicans에 대하여 우수한 억제 활성이 관찰되었고, 특히 세균의 배양상등액 접종실험에서 강한 항균활성을 보였다. 또한, KATB 99121은 전분, 단백질 및 섬유소를 분해하는 효소를 세포외로 분비하는 것으로 관찰되었고, KATB 99122와 KATB 99123은 전분, 단백질, 섬유소 분해효소는 물론 지질 분해효소도 분비하고 있었으며 ${\beta}$-glucosidase활성도 높은 것으로 확인되었다. 앞으로 이들 길항세균들을 이용하여 느타리버섯 푸른곰팡이병 방제를 위한 미생물 살균제의 개발에 대한 연구를 수행할 예정이다.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1244-1251
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• 2020

Phospholipase A₂ (PLA₂) from Streptomyces violaceoruber is a lipolytic enzyme used in a wide range of industrial applications including production of lysolecithins and enzymatic degumming of edible oils. We have therefore investigated expression and secretion of PLA₂ in two workhorse microbes, Pichia pastoris and Escherichia coli. The PLA₂ was produced to an activity of 0.517 ± 0.012 U/ml in the culture broth of the recombinant P. pastoris. On the other hand, recombinant E. coli BL21 star (DE3), overexpressing the authentic PLA₂ (P-PLA₂), showed activity of 17.0 ± 1.3 U/ml in the intracellular fraction and 21.7 ± 0.7 U/ml in the culture broth. The extracellular PLA2 activity obtained with the recombinant E. coli system was 3.2-fold higher than the corresponding value reached in a previous study, which employed recombinant E. coli BL21 (DE3) overexpressing codon-optimized PLA₂. Finally, we observed that the extracellular PLA₂ from the recombinant E. coli P-PLA₂ culture was able to hydrolyze 31.1 g/l of crude soybean lecithin, an industrial substrate, to a conversion yield of approximately 95%. The newly developed E. coli-based PLA₂ expression system led to extracellular production of PLA₂ to a productivity of 678 U/l·h, corresponding to 157-fold higher than that obtained with the P. pastoris-based system. This study will contribute to the extracellular production of a catalytically active PLA₂.

• Journal of Microbiology and Biotechnology
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• 제26권2호
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• pp.315-325
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• 2016

A novel esterase gene, est7K, was isolated from a compost metagenomic library. The gene encoded a protein of 411 amino acids and the molecular mass of the Est7K was estimated to be 44,969 Da with no signal peptide. Est7K showed the highest identity of 57% to EstA3, which is an esterase from a drinking water metagenome, when compared with the enzymes with reported properties. Est7K had three motifs, SMTK, YSV, and WGG, which correspond to the typical motifs of family VIII esterases, SxxK, Yxx, and WGG, respectively. Est7K did not have the GxSxG motif in most lipolytic enzymes. Three additional motifs, LxxxPGxxW, PLGMxDTxF, and GGxG, were found to be conserved in family VIII enzymes. The results of the phylogenetic analysis and the alignment study suggest that family VIII enzymes could be classified into two subfamilies, VIII.1 and VIII.2. The purified Est7K was optimally active at 40ºC and pH 10.0. It was activated to exhibit a 2.1-fold higher activity by the presence of 30% methanol. It preferred short-length p-nitrophenyl esters, particularly p-nitrophenyl butyrate, and efficiently hydrolyzed glyceryl tributyrate. It did not hydrolyze β-lactamase substrates, tertiary alcohol esters, glyceryl trioleate, fish oil, and olive oil. Est7K preferred an S-enantiomer, such as (S)-methyl-3-hydroxy-2-methylpropionate, as the substrate. The tolerance to methanol and the substrate specificity may provide potential advantage in the use of the enzyme in pharmaceutical and other biotechnological processes.

• Journal of Microbiology and Biotechnology
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• 제24권11호
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• pp.1484-1489
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• 2014

A novel esterase gene, est01, was successfully unearthed from a biogas digester microbiota metagenomic library. The 1,194 bp est01 gene encodes a protein of 44,804 Da (designated Est01). The amino acid sequence of Est01 shows only moderate (33%) identity to a lipase/esterase. Phylogenetic analysis and biochemical characterization confirmed that Est01 is a new member of family VIII esterases. The purified Est01 from recombinant Escherichia coli BL21 (DE3) showed high hydrolytic activity against short-chain fatty acid esters, suggesting that it is a typical carboxylesterase rather than a lipase. Furthermore, the Est01 was even active at $10^{\circ}C$ (43% activity remained), with the optimal temperature at $20^{\circ}C$, and had a broad pH range from 5.0 to 10.0, with the optimal pH of 8.0. These properties suggest that Est01 is a cold-adaptive esterase and could have good potential for low-temperature hydrolysis application.