• 한국식품영양과학회지
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• 제32권8호
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• pp.1206-1213
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• 2003

탁주의 기능성 강화를 위하여 율무를 첨가하여 제조한 탁주의 탁주로서의 적합성을 조사하였다. 우선 기존 쌀코오지를 이용하여 전분원으로서 율무를 15, 30, 60와 100% 첨가했을 경우, 효모의 균수와 ethanol의 생성량은 각각 9.5${\times}$$10^{7}$ ∼2.3${\times}$$10^{8}$ cell/mL과 13.6∼15.2%로 시료 간의 큰 차이를 보이지 않아 율무의 알콜 발효원으로 적합성을 보여주었다. 한편 고급알콜인 iso-amyl alcohol은 첨가된 율무량에 따라 1,150ppm으로부터 1,206, 1,213, 1,293, 1,604 ppm으로 각각 증가되고, acetaldehyde와 iso-butanol도 율무의 첨가량에 따라 증가하였다. 한편 Aspergillus kawachii(AK)와 ifhizopus japonicus(RJ)를 이용하여 율무누룩주를 만든 결과 ethanol 생성량은 쌀코오지로 만든 율무주에 비해 14%로부터 각각 11.2%(AK), 7.5%(RJ) 그리고 10.4%(AK+ RJ)로 감소하였고, 효모의 수는 7.5${\times}$$10^{7}$ ∼2.6${\times}$$10^{8}$ cell/mL이었으며, isoamyl alcohol 함량이 1,840 ppm으로부터 각각 632[AK], 855[RJ], 792 ppm[AK+RJ]로 감소하였고, n-propanol, iso-butanol 등의 fusel oil도 감소하였으나, acetaldehyde가 57ppm으로부터 99[AK], 138[RJ], 131 ppm[AK+RJ]으로 각각 증가되었다. 전체적으로 탁주제조에 있어 율무의 이용은, 전분원으로서 사용하는 경우 알콜 발효와 관능검사에는 큰 영향을 미치지 않았으나 fusel oil의 함량이 증가하였고, 누룩을 원료로서 사용하는 경우ethanol의 생성과 fusel oil의 생성이 감소하고, acetaldehyde의 함량이 현격히 증가하였으며, 관능검사 결과 기호도가 낮아졌다.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.260-264
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• 1999

The combined activities of dextranase and amylase(DXAMase) from Lipomyces starkeyi KSM 22 produced from starch fermentation inhibited or prevented dental plaque formation. The activities were stable in commercial mouthwash products; DXAMase activity retained over 93％ of original activity after 6 months at 23℃. We examined the effects of enzyme inhibitors and active ingredients in mouthwash on DXAMase activity. The DXAMase was stable with 0.29％(w/v) EDTA, 20％ (v/v) ethanol, 0.05％ (w/v) fluoride, and 0.05％ (w/v) SDS. Among the active ingredients of mouthwash, sodium benzoate (up to 1 ％, w/v) had no inhibitory effect on either dextranase or amylase activity. In the case of cetylpyridinium chloride, the addition of 0.05％ (w/v) inhibited 6％ of dextranase activity and 13％ of amylase activity. Propylene glycol (up to 1％, w/v) showed no inhibitory effect on either enzyme activity. DXAMase (5 IU/㎖) in mouthwash could remove pre-formed films of glucan-bound S. mutans cells. The addition of 0.1 IU/㎖ DXAMase in mouthwash prevented the formation of insoluble-glucan. These in vitro properties of L. starkeyi KSM 22 DXAMase are desirable for its application as a dental plaque control agent.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.733-738
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• 2007

An extracellular exoinulinase($2,1-\beta-D$ fructan fructanohydrolase, EC 3.2.1.7), which catalyzes the hydrolysis of inulin into fructose and glucose, was purified 23.5-fold by ethanol precipitation, followed by Sephadex G-100 gel permeation from a cell-free extract of Kluyveromyces marxianus YS-1. The partially purified enzyme exhibited considerable activity between pH 5 to 6, with an optimum pH of 5.5, while it remained stable(100%) for 3 h at the optimum temperature of $50^{\circ}C$. $Mn^{2+}\;and\;Ca^{2+}$ produced a 2A-fold and 1.2-fold enhancement in enzyme activity, whereas $Hg^{2+}\;and\;Ag^{2+}$ completely inhibited the inulinase. A preparation of the partially purified enzyme effectively hydrolyzed inulin, sucrose, and raffinose, yet no activity was found with starch, lactose, and maltose. The enzyme preparation was then successfully used to hydrolyze pure inulin and raw inulin from Asparagus racemosus for the preparation of a high-fructose syrup. In a batch system, the exoinulinase hydrolyzed 84.8% of the pure inulin and 86.7% of the raw Asparagus racemosus inulin, where fructose represented 43.6mg/ml and 41.3mg/ml, respectively.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1337-1350
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• 2023

Caproic acid is a precursor substance for the synthesis of ethyl caproate, the main flavor substance of nongxiangxing baijiu liquor. In this study, Clostridium butyricum GD1-1, a strain with high caproic acid concentration (3.86 g/l), was isolated from the storage pit mud of nongxiangxing baijiu for sequencing and analysis. The strain's genome was 3,840,048 bp in length with 4,050 open reading frames. In addition, virulence factor annotation analysis showed C. butyricum GD1-1 to be safe at the genetic level. However, the annotation results using the Kyoto Encyclopedia of Genes and Genomes Automatic Annotation Server predicted a deficiency in the strain's synthesis of alanine, methionine, and biotin. These results were confirmed by essential nutrient factor validation experiments. Furthermore, the optimized medium conditions for caproic acid concentration by strain GD1-1 were (g/l): glucose 30, NaCl 5, yeast extract 10, peptone 10, beef paste 10, sodium acetate 11, L-cysteine 0.6, biotin 0.004, starch 2, and 2.0% ethanol. The optimized fermentation conditions for caproic acid production by C. butyricum GD1-1 on a single-factor basis were: 5% inoculum volume, 35℃, pH 7, and 90% loading volume. Under optimal conditions, the caproic acid concentration of strain GD1-1 reached 5.42 g/l, which was 1.40 times higher than the initial concentration. C. butyricum GD1-1 could be further used in caproic acid production, NXXB pit mud strengthening and maintenance, and artificial pit mud preparation.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2005년도 2005 Annual Meeting & International Symposium
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• pp.154-164
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• 2005

Saccharomyces cerevisiae KNU5377 is a thermotolerant strain, which can ferment ethanol from wasted papers and starch at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. This strain showed alcohol fermentation ability to convert wasted papers 200 g (w/v) to ethanol 8.4% (v/v) at 40$^{\circ}C$, meaning that 8.4% ethanol is acceptable enough to ferment in the industrial economy. As well, all kinds of starch that are using in the industry were converted into ethanol at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. Hyperthermic cell killing kinetics and differential scanning calorimetry (DSC) revealed that exponentially growing cells of this yeast strain KNU5377 were more thermotolerant than those of S. cerevisiae ATCC24858 used as a control. This intrinsic thermotolernace did not result from the stability of entire cellular components but possibly from that of a particular target. Heat shock induced similar results in whole cell DSC profiles of both strains and the accumulation of trehalose in the cells of both strains, but the trehalose contents in the strain KNU5377 were 2.6 fold higher than that in the control strain. On the contrary to the trehalose level, the neutral trehalase activity in the KNU5377 cells was not changed after the heat shock. This result made a conclusion that though the trehalose may stabilize cellular components, the surplus of trehalose in KNU5377 strain was not essential for stabilization of whole cellular components. A constitutively thermotolerant yeast, S. cerevisiae KNU5377, was compared with a relatively thermosensitive control, S. cerevisiae ATCC24858, by assaying the fluidity and proton ATPase on the plasma membrane. Anisotropic values (r) of both strains were slightly increased by elevating the incubation temperatures from 25$^{\circ}C$ to 37$^{\circ}C$ when they were aerobically cultured for 12 hours in the YPD media, implying the membrane fluidity was decreased. While the temperature was elevated up to 40$^{\circ}C$, the fluidity was not changed in the KNU5377 cell, but rather increased in the control. This result implies that the plasma membrane of the KNU5377 cell can be characterized into the more stabilized state than control. Besides, heat shock decreased the fluidity in the control strain, but not in the KNU5377 strain. This means also there's a stabilization of the plasma membrane in the KNU5377 cell. Furthermore, the proton ATPase assay indicated the KNU5377 cell kept a relatively more stabilized glucose metabolism at high temperature than the control cell. Therefore, the results were concluded that the stabilization of plasma membrane and growth at high temperature for the KNU5377 cell. Genome wide transcription analysis showed that the heat shock responses were very complex and combinatory in the KNU5377 cell. Induced by the heat shock, a number of genes were related with the ubiquitin mediated proteolysis, metallothionein (prevent ROS production from copper), hsp27 (88-fold induced remarkably, preventing the protein aggregation and denaturation), oxidative stress response (to remove the hydrogen peroxide), and etc.

• 한국식품영양학회지
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• 제22권1호
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• pp.86-91
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• 2009

To develop a new traditional Gugija tagju, various koji were prepared using several starch sources along with Aspergillus awamori var. kawachi, and then their effects on the quality of the tagju were investigated. Ethanol contents(11.1${\sim}$13.8%) were not significantly different among the Gugija tagju made from the various types of koji, whereas the tagju made using non-glutinous rice koji had the best total acceptability. The addition of 1% Gugija extracts into the mash increased its total acceptability and anti-hypertensive angiotensin I-converting inhibitory activity, and the optimal fermentation period for brewing the Gugija tagju was 10 days.

• 한국미생물·생명공학회지
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• 제35권3호
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• pp.231-237
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• 2007

전통주의 다양성과 국내 누룩의 우수성을 확보하기 위한 연구의 일환으로, 민속주 안동소주의 자가 제조 누룩의 최적 제조조건을 검토하였다. 안동소주 제조의 전통적인 누룩 제조방법을 준수하면서 23 cm 지름의 $2.2{\sim}5.5\;cm$의 다양한 두께의 누룩을 성형하고, 3주간 띄움 과정을 거치면서 1주일 간격으로 수분함량, pH, brix, 무게변화, 전분 당화능, 환원당 함량, 생균수 및 우점종 변화 등을 조사하였다. 그 결과 두께 4.0 cm 이상으로 성형된 누룩이 전분 당화능력 및 생균수, 누룩 곰팡이 생육면에서 가장 우수하였으며, 에탄올 발효면에서는 2주간의 띄움이, 안동소주의 누룩곰팡이를 이용한 관능적 측면에서는 3주간의 띄움이 필요하다고 판단되었다. 실제 제조된 누룩으로 포도당 및 전분 발효배지에서 에탄을 발효시킨 결과, 누룩 성형시 $4.0{\sim}5.5\;cm$ 두께로 성형하여 $2{\sim}3$주간 누룩을 띄운 경우가 가장 우수한 결과를 나타내었다. 또한 누룩 제조시 별도의 건조효모 첨가는 불필요함을 확인하였다. 본 연구결과는 전통적인 안동소주 제조법하에서 자가제조 누룩의 두께와 띄움시간을 조정하여 누룩의 균일 제조과 효율적인 생산이 가능함을 제시하고 있다.

• 생명과학회지
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• 제28권7호
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• pp.827-834
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• 2018

본 연구는 유용 미생물을 이용하여 흰점박이 꽃무지 유충을 발효시킨 분말을 수용성, 에탄올, 메탄올 용매별 추출하여 항산화 등의 실험에 임하였다. 발효 균주로는 3종의 유산균 Lactobacillus plantarum JBMI F3, Lactobacillus plantarum JBMI F5, Lactobacullus gasseri Ba9, 1종의 곰팡이 Aspergillus kawachii KCCM 32819, 1종의 효모 Saccharomyces cerevisiae KACC 93023, 1 종의 바실러스 Bacillus subtilis KACC 91157 총 6종의 유용 미생물 균주를 사용하였다. 발효 굼벵이 분말 추출물의 유효성분(총 페놀 함량 및 플라보노이드 함량)과 생리 활성 효능(DPPH 자유 라디칼 소거 활성, 환원력 실험, 혈전용해능, ${\alpha}-amylase$ 활성)을 비교 검토하였다. 총 페놀 함량 및 플라보노이드 함량은 바실러스 균주 발효 굼벵이 분말의 수용성 추출물에서 높은 수치를 나타내었다. 항산화 활성을 확인하기 위해 DPPH 자유 라디칼 소거능 및 환원력 실험을 수행한 결과, 비발효군 보다 발효군에서 우수한 항산화능을 보였고, 그 중 바실러스 균주를 이용한 발효 추출물이 긍정적인 효과를 나타내었다. 혈전 용해능에서 또한, 바실러스 균주 발효 굼벵이 추출물에서 우수한 혈전 용해능을 확인였고, 효소-기질 분해능 실험의 ${\alpha}-amylase$ 활성은 비발효군보다 발효군에서 높은 효과를 확인하였으나 발효균주간 유의적인 차이는 없었다. 따라서, 유용 미생물을 이용한 발효 굼벵이 추출물의 유용성분 및 생리활성이 강화됨을 확인하였고, 이는 건강 식품 소재로의 이용 가능성이 높다고 판단된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권5호
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• pp.408-413
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• 2006

We assessed the ability of a Pseudonocardia sp. from soil samples to bioconvert vitamin $D_3$. The optimal culture conditions for the bioconversion of vitamin $D_3$ to active $1{\alpha}$,25-dihydroxyvitamin $D_3$ were investigated by varying the carbon and nitrogen sources, the metal salt concentrations, the initial pH, and the temperature. Microbial transformations were carried out with the addition of vitamin $D_3$ dissolved in ethanol. They were sampled by extraction with methanol-dichloromethane and the samples were examined by HPLC. Optimum culture conditions were found to be 0.4% yeast extract, 1% glucose, 3% starch, 1% fish meal, 0.2% NaCl, 0.01% $K_2HPO_4$, 0.2% $CaCO_3$, 0.01% NaF, and pH 7.0 at $28^{\circ}C$. The optimal timing of the addition of vitamin $D_3$ for the production of calcitriol by Pseudonocardia autotrophica ID9302 was concurrent with the inoculation of seed culture broth. Maximum calcitriol productivity and the yield of bioconversion reached a value of 10.4mg/L and 10.4% respectively on the 7th day in a 75L fementer jar under the above conditions.

• Food Science and Biotechnology
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• 제15권1호
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• pp.24-27
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• 2006

A simple HPLC quantification method was developed for genistein, genistin, daidzein, and daidzin in soybeans and soybean products. The procedure used a $4.6{\times}100\;mm$ $Chromolith^{(R)}$ RP-18e column with a mobile phase of 1% HOAc in 20% MeOH to 1% HOAc in 80% MeOH for 10 min. The injection volume was $2\;{\mu}L$ at a flow rate of 2 mL/min. Detection was carried out under UV at 254 nm. Under these conditions, the major isoflavones daidzein, daidzin, genistein, and genistin in soybean and soybean pastes were eluted within 7 min with baseline separation. Optimal extraction of the above four major isoflavones was achieved when 40 g of soybean or soybean paste was refluxed in 100 mL of 95% ethanol for 2 hr. Ten different soybean cultivars and nine commercial soybean pastes were analyzed by this method. The total isoflavone content was highest in the cultivar Somyung ($2,497\;{\mu}g/g$ dry weight). The isoflavone content in soybean pastes varied widely from manufacturer to manufacturer (an almost five-fold difference between the highest and lowest values). Such variations were presumably due to differences in fermentation conditions, type of soybeans used, and levels of such additives as starch and salt.