• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.8-8
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• 2019

The stringent response (SR) is characterized as a bacterial defense mechanism in response to various growth-inhibiting stresses. It is activated by accumulation of a small nucleotide regulator, (p)ppGpp, and induces global changes in bacterial transcription and translation. Recent work from our group has shown that (p)ppGpp plays a critical role in virulence and survival in Vibrio cholerae. The genes, relA and relV, are involved in the production of (p)ppGpp, while the spoT gene encodes an enzyme that hydrolyzes it in V. cholerae. A mutant strain defective in (p)ppGpp production (i.e. ${\Delta}relA{\Delta}relV{\Delta}spoT$ mutant) lost the ability to produce cholera toxin (CT) and lost their viability due to uncontrolled production of organic acids, when grown with extra glucose. In contrast, the ${\Delta}relA{\Delta}spoT$ mutant, a (p)ppGpp overproducer strain, produced enhanced level of CT and exhibited better growth in glucose supplemented media via glucose metabolic switch from organic fermentation to acetoin, a neutral fermentation end product, fermentation. These findings indicates that (p)ppGpp, in addition to its well-known role as a SR mediator, positively regulates CT production and maintenance of growth fitness in V. cholerae. This implicates SR as a promising drug target, inhibition of which may possibly downregulate V. cholerae virulence and survival fitness. Therefore, we screened a chemical library and identified a compound that induces medium acidification (termed iMAC) and thereby loss of wild type V. cholerae viability under glucose-rich conditions. Further, we present a potential mechanism by which the compound inhibits (p)ppGpp accumulation. Together, these results indicate that iMAC treatment causes V. cholerae cells to produce significantly less (p)ppGpp, an important regulator of the bacterial virulence and survival response, and further suggesting that it has a therapeutic potential to be developed as a novel antibacterial agent against cholera.

• 한국식품과학회지
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• 제29권6호
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• pp.1295-1303
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• 1997

본 연구는 치커리추출물 첨가가 in vitro에서 전분가수분해율 및 정상성인에서의 혈당반응에 미치는 영향을 실험하였다. In vitro 실험에서 고형분량으로 계산된 5% (w/w) 건조치커리 및 볶은치커리추출물을 전분용액에 각각 첨가하고 2시간 동안 가수분해시킨 후 15, 30, 60, 90, 120분에 각각 유리된 당을 측정하여 전분가수분해율 및 전분가수분해지수를 구하였다. 정상 성인을 대상으로한 실험에서는 고형분량으로 계산된 2.5, 5, 10및 20% (w/w) 건조치커리 및 볶은치커리추출물을 각각 포도당용액(60 g/300 mL)에 첨가하여 섭취시킨 다음 공복시 혈당 및 실험용액 섭취후 15, 30, 60, 90, 120, 150분에 각각 혈당을 측정하고 혈당반응 면적 및 혈당지수를 구하였다. 본 실험결과, 전분에 5% 건조치커리 및 볶은치커리추출물 첨가는 2시간 동안의 전분가수분해율, 가수분해면적 및 가수분해지수를 유의하게 감소시켰으나(p<0.05), 건조치커리군과 볶은치커리군사이의 유의적인 차이는 없었다. 포도당 용액에 2.5, 5, 10, 20% 건조치커리 및 볶은치커리추출물을 첨가했을때 모든 실험군에서 혈당곡선면적 및 최고혈당값은 낮아졌으며 최고혈당값을 나타내는 시간이 지연되는 경향을 보였다. 포도당 섭취시와 비교하여 모든 건조치커리군과 5, 10 및 20% 볶은치커리군의 혈당지수는 유의하게 감소되었으며(p<0.05), 특히 5 및 10% 건조치커리군의 혈당지수는 36%씩 감소되었고 20% 볶은치커리군의 경우 39% 감소되었다. In vitro 및 in vivo 실험결과로 볼때 치커리추출물첨가는 식후 혈당증가를 낮출 것으로 사료된다.

• Journal of Yeungnam Medical Science
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• 제12권2호
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• pp.319-330
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• 1995

임신시 발생하는 인슐린 저항성과 인슐린 분비 증가의 기전을 규명하기 위하여 Sprague-Dawley 종 암컷 흰쥐를 이용하여 정맥당부하 검사와 호르몬 및 지방 대사물질과 조직에서의 인슐린 수용체 결합, 당원질 합성효소를 분석한 결과를 요약하면 다음과 같다. 정맥당부하검사에서 임신군에서 전체적인 곡선이 대조군에 비하여 아래에 위치하였다. 그러나 당부하시 인슐린 분비는 현저히 증가하였으며 혈당에 대한 비(${\mu}U/mg$)로 비교하여 임신군에서 $56.9{\pm}8.9$였고 대조군에서 $23.6{\pm}2.8$로서 인슐린 저항성을 확인할 수 있었다. 인슐린 분비반응의 증가는 태반 호르몬인 progesterone의 증가와 강한 상관관계를 나타내었다. 당부하검사후 당원질 (mg/100mg tissue)은 골격근(soleus)에서는 임신군과 대조군간에 유의한 차이가 없었으나 간조직에서는 임신군에서 $4.7{\pm}0.9$으로 대조군의 $9.9{\pm}1.3$에 비하여 통계적으로 유의하게 감소하였다. 당원질로 합성된 $^{14}C$-glucose의 활동도도 마찬가지로 골격근에서는 임신군과 대조군간에 유의한 차이가 없었으나 간조직에서는 현저한 감소를 보였다. 당원질 합성 효소(glycogen synthase)는 골격근에서는 대조군이 높았고 간장조직에서는 임신군이 높았으나 유의한 차이는 없었다. 당부하검사후 간장조직의 crude membrane에서의 인슐린-인슐린 수용체 결합반응에서는 두 군 사이에 유의한 차이가 없었다. 이상의 결과로 보아 정상임신흰쥐에서 인슐린 저항성이 발생하였으나 인슐린 분비의 현저한 증가로 내당능의 감소는 나타나지 않았으며 인슐린의 분비증가는 progesterone의 증가와 상관관계가 있었다. 인슐린 저항성은 간에서 가장 현저하게 나타났으며 그 원인은 인슐린 수용체의 결합과정보다는 수용체 전 과정이거나 수용체 후 과정일 것으로 추정된다.

• Preventive Nutrition and Food Science
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• 제10권1호
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• pp.52-57
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• 2005

Soy and soy foods are a rich source of isoflavones, which possess several biological activities. The effect of soy isoflavones, genistin and diadzin and their respective aglycones, on glucose uptake in adipocytes isolated from normal or high-fat fed rats was examined. As expected, insulin stimulated glucose uptake in a concentration-dependent manner. However, genistin and daidzin and their aglycones inhibited glucose uptake in a concentration-dependent (25-100μM) manner. In a time-course response, the aglycones significantly inhibited glucose uptake throughout 3 hr (after 30, 60, 120, 180 min), whereas the glycones only significantly inhibited the glucose uptake after 120 min and 180 min in the isolated rat adipocytes. Thus, the glucosides of genistein and daidzein, i.e. genistin and daidzin, were much less effective in inhibiting glucose uptake than their aglycones. In addition, genistin and daidzin did not significantly affect the insulin-stimulated glucose uptake, whereas genistein and daidzein did significantly inhibited glucose uptake compared to the vehicle control group by 47.5% and 24.8%, respectively (p < 0.05). The isoflavones also significantly inhibited glucose uptake in adipocytes isolated from rats fed a high-fat diet (50% of total calorie intake) when compared to the vehicle control. Finally, the isoflavones were found to enhance lipolysis in adipocytes isolated from high-fat fed rats, where the glycerol released by the aglycones was also higher than that released by the glycones. The current results showed that the inhibitory effect of daidzein on glucose uptake was very similar to that of genistein. The aglycones were more potent in inhibiting the uptake of glucose and a more potent stimulator of lypolysis than the glycones in adipocytes isolated from high-fat fed rats.

• 한국식품영양학회지
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• 제8권4호
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• pp.318-324
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• 1995

The purpose of this study was to Investigate the response of fasting serum glucose and basal insulin to dietary omega-3 fatty fish in normal subjects. Nineteen healthy female volunteer subjects were divided into two groups, depending on fish preference test. Low ap3 fatty acid group for 7 days received a experimental Inlet containing mackeral fish 100g. Calorie intake was 1780 kcal /day. The average 4ally u-3 fatty acid consumption from fish was 3.87g /day (1.03g EPA, 2.849 DHA) . High n-3 fatty acid group was given 7.74g maine u-3 fatty acid (200g mackeral fish) consisting of 2.06g EP45.68g DHA. Calorie intake was 1815 local /day Fasting blond serum glucose, insulin levels were measured at baseline, 7days after experimental diet. In the beginning the levels of fasting serum glucose, basal insulin were not different between both groups. There were no significant changes in fasting serum glucose, insulin levels by experimental diets. These data indicate that marine ar3 fatty acid consumption have no deleterious effect on glycemic control in normal subjects.

• 한국미생물·생명공학회지
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• 제26권2호
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• pp.96-101
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• 1998

여러 가지 외부 탄소원(acetic acid, glucose, methanol, molasses)으로 활성 슬러지를 이용하여 탈질 효과를 살펴보았다. 질산성 질소와 아질산성 질소를 질소원으로 하는 혐기성 슬러지의 회분식 배양을 통해 탈질속도, COD 소비, 탈질율을 조사해 본 결과 molasses는 탈질속도나 COD 소비에서 glucose와 비슷하고 acetic acid나 methanol보다 높았으나, 탈질 효율에 있어서는 질산성 질소나 아질산성 질소배지에서 30-40%가 암모니아로 축적되어 탈질 효율이 떨어졌다. 이러한 현상은 molasses와 glucose를 탄소원으로 이용한 경우 발효에 의해 pH저하를 초래하고 이로 인해 탈질 효율이 감소되는 것으로 생각된다. 따라서 초기 pH를 조절하고 외부 탄소원은 molasses를 이용, 탈질 효과를 조사한 결과 pH 8일 때 암모니아의 축적은 거의 없었으며 탈질 속도에 있어서도 acetic acid의 경우보다 12시간정도 빠른 24시간 안에 99% 이상 탈질 효율이 증가함을 알 수 있었다.

• 대한핵의학회지
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• 제7권1호
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• pp.31-38
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• 1973

The blood glucose and plasma immunoreactive insulin(IRI) levels were measured glucose tolerance test in 7 healthy subjects and 6 patients with chronic liver diseases. The glucose tolerance was impaired in 5 of the 6 patients and normal in 1. Plasma IRI responses were markedly increased and delayed in all patients, suggesting insulin resistance. Patients with more glucose intolerance showed less increase in plasma IRI than the group with less intolerance. It is suggested that some insulin antagonists may decrease the peripheral insulin sensitivity and stimulate compensatory hyperactivity of pancreatic islets. If the compensatory hyperactivity is inadequate due to genetic predisposition to diabetes mellitus or exhaustion of ${\beta}$-cells of pancreatic islsts, the glucose intolerance and overt diabetes mellitus may ensue.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.449-456
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• 2002

The objective of this study was to optimize medium composition of initial pH, tryptone, glucose, yeast extract, and mineral mixture for production of bacteriocin by Lactobacillus acidophilus ATCC 4356, using response surface methodology. A response surface approach including new statistical and plotting methods was employed for design and analysis of the experiment. An interiorly augmented central composite design was used as an experimental design. A normal-distribution log-link generalized linear model based on a subset fourth-order polynomial ($R^2$=0.94, Mean Error Deviance=0.0065) was used as an analysis model. This model was statistically superior to the full second-order polynomial-based generalized linear model ($R^2$=0.80, Mean Error Deviance=0.0140). Nonlinear programming determined the optimum composition of the medium as initial pH 6.35, typtone $1.21\%$, glucose $0.9\%$, yeast extract $0.65\%$, and mineral mixture $1.17\%$. A validation experiment confirmed that the optimized medium was comparable to the MRS medium in bacteriocin production, having the advantage of economy and practicality.

• 한국식품과학회지
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• 제18권4호
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• pp.259-263
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• 1986

검 형태의 인삼젤리에 대하여 조직감 특성 중 견고성을 반응표면 실험계획법으로 조사하여 본 결과 각성분이 제품의 견고성에 미치는 영향을 회귀방정식$({R_A}^2=0.8660)$으로 나타낼 수 있었고, 2가지 원료가 견고성에 미치는 경향을 등고선 그림(response surface contour)을 통하여 관찰 하였다. 1차적인 영향은 구성성분 중 포도당 시럽>젤라틴>설탕>수분>crtric acid순 이었으며 이중 수분과 포도당 시럽의 경우는 교호작용에 의한 영향도 매우 큰 것으로 나타났다.

• Preventive Nutrition and Food Science
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• 제7권4호
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• pp.397-404
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• 2002

Soybean curd residue (SCR) was fermented by lactic acid bacteria, Lactobacillus rhamnosus LS and Entercoccus faecium LL, isolated from SCR. The pH, titratable acidify and viable cell counts were determined from the fermented SCR to evaluate the lactic acid production and growth of lactic acid bacteria. Optimal amounts of pretense enzyme and glucose, and ideal fermentation time for SCR fermentation were estimated by response surface methodology (RSM). Raw SCR fermented by indigenous microorganisms had 0.78 % titratable acidity, The acid production in SCR fermented by L. rhamnosus LS was greatly enhanced by the addition of glucose and lactose. However only glucose increased acid production by Ent. faecium LL. The proof test of SCR fermentation demonstrated that similar results for titratable acidity, tyrosine content and viable cell counts to that predicted could be obtained by the at optimized fermentation conditions. In the presence of 0.029 % (w/w) pretense enzyme and 0.9% (w/w) glucose, the SCR fermented by Ent. faecium LL showed 1.07% (w/v) of titratable acidity, 1.02 mg% tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts. With the SCR fortified with 0.033% pretense enzyme and 1.7% glucose, L. rhamnosus LS showed 1.8% (w/v) of titratable acidity, 0.92 mg% of tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts.