• 한국식품영양과학회지
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• 제13권1호
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• pp.64-70
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• 1984

감압 저장 중 tomato과실에서 일어나는 당전환의 일부를 조사 하고자 저장기간을 통하여 탄수화물의 성분과 그들에 관련된 효소활성 변화를 조사한 결과는 다음과 같다. tomato 과실에 함유되어 있는 soluble sugar의 대부분은 fructose glucose이며 소량의 sucrose와 maltose가 존재하였다. 이들의 저장 중 변화를 살펴보면 fructose는 저장전반에 걸쳐 증가하는 경향이었고, glucose는 저장초기에 증가하다가 저장말기에 약간 감소하였으며 sucrose는 저장시일이 경과함에 따라 급격히 감소하는 경향이었다. 당전환에 중요한 역할을 하는 ${\alpha}-amylase$와 in-vertase의 활성은 climacteric onset 시기에 급격히 증가하였으며 이로 인하여 이 시기에 total soluble sugar는 급격히 증가하는 반면 기질인 starch와 sucrose는 현저히 감소하는 경향이었다. 이러한 경향은 압력에 의한 영향보다 온도에 따른 영향이 더 크게 나타났다.

• Journal of Ginseng Research
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• 제42권4호
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• pp.412-418
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• 2018

Background: Ginsenoside Rg3(S) and compound K (C-K) are pharmacologically active components of ginseng that promote human health and improve quality of life. The aim of this study was to produce Rg3(S) and C-K from ginseng extract using recombinant Lactococcus lactis. Methods: L. lactis subsp. cremoris NZ9000 (L. lactis NZ9000), which harbors ${\beta}$-glucosidase genes (BglPm and BglBX10) from Paenibacillus mucilaginosus and Flavobacterium johnsoniae, respectively, was reacted with ginseng extract (protopanaxadiol-type ginsenoside mixture). Results: Crude enzyme activity of BglBX10 values comprised 0.001 unit/mL and 0.003 unit/mL in uninduced and induced preparations, respectively. When whole cells of L. lactis harboring pNZBglBX10 were treated with ginseng extract, after permeabilization of cells by xylene, Rb1 and Rd were converted into Rg3(S) with a conversion yield of 61%. C-K was also produced by sequential reactions of the permeabilized cells harboring each pNZBgl and pNZBglBX10, resulting in a 70% maximum conversion yield. Conclusion: This study demonstrates that the lactic acid bacteria having specific ${\beta}$-glucosidase activity can be used to enhance the health benefits of Panax ginseng in either fermented foods or bioconversion processes.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.657-663
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• 1998

The enzyme responsible for the synthesis of nitric oxide (NO) from L-arginine in mammalian tissues is known as nitric oxide synthase (NOS) (EC.1.14.13.39). In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat pancreatic acinar cells. Treatment of rat pancreatic acinar cells with cholecystokinin-octapeptide (CCK-OP) resulted in an increase in the arginine conversion to citrulline, the amount of $NO_X$, the release of amylase, and the level of CGMP. Especially, CCK-OP-stimulated increase of arginine to citrulline transformation, the amount of $NO_X$, and CGMP level were completely counteracted by the inhibitor of NOS, NG-monomethyl-L-arginine (MMA), by contrast, that of amylase release was partially reduced. Furthermore, MMA-induced decrease of NOS activity and amylase release showed dose-dependent pattern. The data on the time course of CCK-OP-induced citrulline formation and CGMP rise indicate that NOS and guanylate cyclase were activated by treatment of CCK-OP. However, the mechanism of agonist-stimulated guanylate cyclase activation in acinar cells remains unknown. Therefore, activation of NOS is one of the early events in receptor-mediated cascade of reactions in pancreatic acinar cells and NO, not completely, but partially mediate pancreatic enzyme exocrine secretion.

• 한국버섯학회지
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• 제14권2호
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• pp.70-74
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• 2016

본 연구에서는 버섯 수확후배지를 바이오매스로 활용하고자 수행하였으며, 적정 전처리 조건을 구명한 결과는 다음과 같다. 버섯 수확후 배지의 전처리방법 중 알카리 처리가 리그닌 함량을 효과적으로 경감시키면서, 당전환율이 우수하였고 큰느타리 수확후 배지가 당전환율 80.7%로 가장 우수하였다. 큰느타리 수확후 배지에 1% NaOH를 이용한 알카리 처리시 전처리 온도별 성분분석 결과 $120^{\circ}C$처리시에 glucose 25.3%, xylose 14.8%로 유리당 함량이 가장 높고, 효소에 의한 당전환율도 66%로 무처리구 28.2%에 비해 2.3배 증가되었다. 촉매제 농도(NaOH 0.5~2.0%)에 따른 당분석결과 glucose 함량은 촉매제 농도와 관계가 적었으며, xylose와 arabinose는 촉매제 농도가 높을수록 다소 감소하는 경향이었다. 그러나 당전환율은 NaOH 1% 처리시에 66%로 가장 높았다.

• 한국축산식품학회지
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• 제38권4호
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• pp.806-815
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• 2018

This study was performed to isolate some strains of Bifidobacterium breve from fecal materials of neonates and to screen them for the biotransformation activity of converting linoleic acid into conjugated linoleic acid (CLA). Fecal samples were collected from twenty healthy neonates between 14 and 100 days old, and four hundred colonies were randomly selected from a Bifidobacterium selective transoligosaccharide medium. A duplex polymerase chain reaction technique was developed for the rapid and accurate molecular characterization of the B. breve strains that have been reported to show the species-specific characteristic of CLA production. They are identified by 16S ribosomal DNA, fructose-6-phosphate phosphoketolase encoding genes (xfp), and rapid pulsed field gel electrophoresis. Thirty-six isolates were identified as B. breve, and just two of the 12 neonates were harboring B. breve strains. Each isolate showed different CLA-producing ability in the spectrophotometric assay. All of the positive strains from the primary spectrophotometric assay were confirmed for their CLA-producing activities using gas-chromatographic analysis, and their conversion rates were different, depending on the strain isolated in this study. Some strains of B. breve were successfully isolated and characterized based on the CLA-producing activity, and further studies are necessary to characterize the enzyme and the gene responsible for the enzyme activity.

• 한국미생물·생명공학회지
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• 제9권1호
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• pp.35-44
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• 1981

대장균이 생산하는 페니실린 아미다제를 젤라틴에 포괄시켜 사출한 후 글루트알데히드로 가교하여 고정화하였다. 이렇게 하여 만들어진 고정화효소는 약 70%의 높은 효소역가를 나타내었고 보관 및 반응조에서 좋은 안정성을 보여주었다. 반응조 내에서의 효소역가 반감기는 약 50일이었으며 최적 PH 및 온도는 각각 8.5와 5$0^{\circ}C$로 나타났다. 효소역가에 미치는 pH 및 온도의 영향은 고정화하기 전과 큰 차이가 없었으나 고온에서의 안정성이 증가되었다. 기질용액으로 완충액을 사용하여 column을 사용하는 관형식 반응조에서의 반응생성률에 기인하는 pH 감소효과를 최소한으로 줄이므로써 효소반응조를 최적화하였다. 반응조 조작상의 중요한 인자 즉 기질농도, 체류시간, 반응 생성물로의 전환율 및 이에 따르는 생산성을 pH 감소효과와 연관시켜 최적반응조건을 논의하였다.

• 생약학회지
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• 제40권4호
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• pp.394-399
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• 2009

Aldose reductase (AR) is a critical enzyme in the development of the diabetic complications. AR, the first enzyme in the polyol pathway, catalyzes the reduction of the aldehyde form of glucose to sorbitol with concomitant conversion of NADPH to $NADP^+$. None of aldose reductase inhibitor (ARI) has achieved worldwide use because of limited efficacy or undesirable side effects. Therefore, evaluating natural sources for ARI potential may lead to the development of safer and more effective agents against diabetic complications. Forty eight Chinese herbal medicines have been investigated for inhibitory activities on AR. Among them, seven herbal medicines, Buddleja officinalis (whole plant), Lonicera japonica (leaf and flower), Polygonum aviculare (aerial part), Polygonum aviculare (whole plant), Salvia miltiorrhiza (root), Schisandra chinensis (stem), and Zanthoxylum armatum (leaf and stem) exhibited a significant inhibitory activity against AR. Particularly, L. japonica and P. aviculare showed two times more potent inhibitory activity than the positive control, 3,3-tetramethyleneglutaric acid (TMG).

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1403-1412
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• 2013

Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with $H_2SO_4$. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant ${\beta}$-glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% $H_2SO_4$ for 30 min at $150^{\circ}C$. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good ${\beta}$-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.557-564
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• 2009

Two experiments were conducted to evaluate the use of various levels of full-fat sunflower seeds (FFSS) on broiler performance and carcass characteristics. In the first experiment, FFSS was included in a basal diet at 70, 140, and 210 g/kg and the $AME_n$ values of the experimental diets were determined. The linear regression equation of $AME_n$ values on rate of inclusion was calculated. Extrapolation value for the $AME_n$ of FFSS at 100% inclusion was 14.22 MJ/kg. In the second experiment, diets containing various levels (0, 70, 140, and 210 g/kg) of FFSS were given to broilers (Ross strain) from 0 to 49 d. At 28 days of age, blood parameters and digestive enzyme activities were determined and carcass parameters were evaluated at 49 days of age. Weight gain, feed intake and feed conversion ratio (FCR) were improved (p<0.05) when broilers were fed various levels of FFSS in the starter and finisher diets. Breast, thigh, gastrointestinal tract and gizzard weight percentages were not affected by dietary treatments; however, liver weight percentage was decreased significantly (p<0.05) and weight of abdominal fat decreased but this effect was not significant. The activities of digestive enzyme (protease and ${\alpha}$-amylase) were not influenced by the treatments. Activity of alkaline phosphatase, concentrations of calcium, phosphorus, glucose, triglyceride, protein, high density lipoprotein (HDL) and low density lipoprotein (LDL) were not affected by incorporation of FFSS in the broiler diet. Although concentration of HDL increased and LDL decreased, these effects were not significant. The results of this study indicate that FFSS can be used at up to 21% in broiler diets without adverse effects on performance or other parameters of chickens.

• Nutritional Sciences
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• 제9권3호
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• pp.212-226
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• 2006

The involvement of arachidonic acid (AA) metabolizing enzyme, lipoxygenase (LOX), in the development of particular tumors in humans has gradually been acknowledged and LOX has emerged as a novel target to prevent or treat human cancers. In the mouse skin carcinogenesis model, which provides an excellent model to study multistage nature of human cancer development, many studies have shown that some of the LOXs are constitutively upregulated in their expression. Moreover, application of LOX inhibitors effectively reduced tumor burdens, which implicates the involvement of LOX in mouse skin tumor development as well. 8S-LOX is a recently cloned LOX, which is specifically expressed in mouse skin after 12-O-tetradecanoyl-phorbol-13-acetate (TPA) treatment but not in normal skin. Unlike other members of the LOX 'family' expressed in mouse skin, this TPA-induced expression of 8S-LOX is prominent only in the skin of the TPA tumor promotion-sensitive strains of mice (SENCAR, CD-1, and NMRI) but not in the promotion-resistant C57BL/6J mice. This is a very unique phenomenon among strains of mice. Constitutive upregulation of 8S-LOX was also found in early stage papillomas and the expression was gradually reduced as the tumors became malignant. Based on these observations, it has been thought that 8S-LOX is involved in TPA-induced tumor promotion as well as in tumor conversion from papillomas to carcinomas. In accordance with this hypothesis, several studies have suggested possible roles of 8S-hydroxyeicosatetraenoic acid (HETE), an AA metabolite of 8S-LOX, in mouse skin tumor development. A clastogenic activity of 8S-HETE was demonstrated in primary keratinocytes and a close correlation between the levels of etheno-DNA adducts and 8S-HETE during skin carcinogenesis was also reported. On the other hand, it has been reported that 8S-LOX protein expression is restricted to a differentiated keratinocyte compartment Moreover, reported findings on the ability of 8S-HETE to cause keratinocyte differentiation appear to be contrary to the procarcinogenic features of the 8S-LOX expression, presenting a question as to the role of 8S-LOX during mouse skin carcinogenesis. In this review, molecular and biological features of 8S-LOX as well as current views on the functional role of 8S-LOX/8S-HETE during mouse skin carcinogenesis are presented.