• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.62-67
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• 2016

Hydrolytic enzyme activities, including those of ${\beta}$-glucosidase, ${\beta}$-glucuronidase, ${\beta}$-xylosidase, ${\beta}$-galactosidase, ${\beta}$-arabinofuranosidase, ${\beta}$-arabinosidase, and ${\beta}$-arabinopyranosidase, which are useful for bioconversion, were explored in lactic acid bacteria isolated from Korean traditional fermented foods. Nine bacterial strains were selected for the fermentation of green tea extract prepared by supercritical fluid extraction. Changes in the concentrations of catechin, epicatechin, epicatechin gallate, epigallocatechin, and epigallocatechin-3-gallate in green tea extract were investigated after fermentation by the selected lactic acid bacteria strains. The strain Leuconostoc mesenteroides MBE1424, which showed the highest ${\beta}$-glucuronidase enzyme activity among the tested bacterial strains, increased the epigallocatechin content of the green tea extract by 60%. In addition, L. mesenteroides MBE1424 was more resistant than the control strain at high temperature and showed a maximum specific growth rate at $40^{\circ}C$. L. mesenteroides MBE1424 was presumed to have an enzyme system containing ${\beta}$-glucuronidase with utility in the bioconversion of green tea extract.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.124-124
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• 2003

해양 심층수는 저온 안정성, 부영양성 및 인공물질에 오염되지 않은 해양수로서 오늘날 많은 분야에서 사용 가능성이 대두되고 있다. 해양 심층수를 음료나 식품, 화장품 등에 이용하였을 경우 나타나는 효과의 일부는 미네랄 특성과 관계가 있는 것으로 알려져 있으며, 심층수를 원료로 한 음료수에는 혈행개선 효과가 있으며, 심층수를 생수로 섭취하였을 경우 혈중 콜레스테롤치을 유의적으로 낮추는 것으로 알려져 있으며, 간장의 인지질 값도 낮춘다는 연구보고가 있다. 또한 해양심층수는 아토피성 피부염에 효과가 있으며, 식품의 맛을 개선하는 것으로도 알려져 있다. 우리나라의 대표적인 음식인 김치는 배추, 무 둥을 식염으로 절여 각종 채소류 및 향신료를 첨가한 후 젖산발효를 적절하게 시켜 숙성한 채소발효식품으로 세계적인 음식으로서 각광받고 있다. 이 중 무는 천일염이나 정제염에 절여서 깍두기나 동치미 등에 사용되기도 하며, 김치의 재료로 배추 다음으로 이용율이 높은 김치소재이다. 무는 절임여하에 따라서 김치의 맛, 품잘, 미생물의 번식속도, 저장성 등이 변화하며, 절임이 중요한 품질요소로 알려져 있다. 소금의 종류 및 소금의 사용방법에 따른 무의 품질특성의 변화에 대한 연구들이 있으나 해양 심층수염을 이용하여 무를 절임시 품질특성에 대한 연구는 이루어져 있지 않는 실정이다. 이에 본 실험에서는 해양 심층수염에 무의 절임에 따라 무의 절임 특성 변화를 관찰하였다. 해양 심층수염과 천일염을 이용하여 무를 절임할 경우 수축율, 염도, 물성의 특성 변화를 관찰하였다. 해양 심층수염을 가지고 무를 절임할 경우 특성 변화를 살펴본 결과 수축률은 절임 8시간 이후에 해양 심층수염으로 절임한 경우가 천일염으로 절임한 경우보다 큰 것으로 나타났으며, 해양 심층수염이 천일염보다 더 높은 염도를 나타내며 절임되었다. 젤리강도는 절임시간이 증가함에 따라 감소하는 경향을 나타내었으며, 절임 염도가 높을수록 젤리강도는 낮아지는 경향을 나타내었다. 무의 연도(Softness)는 심층수염이 천일염보다 높은 값을 나타냄으로서 해양 심층수염에 절일 때 더 부드러운 물성을 나타냄을 볼 수 있었다. 견고성은 해양 심층수염에 절임하는 것이 천일염에 절임하는 것보다 더 높은 값을 나타났다. 해양 심층 수염이 천일염보다 빨리 무 조직에 손상을 줌으로 절임을 단축시키지만 절임시간이 연장되면 오히려 무 조직의 손상을 완화시키는 것으로 나타났다. 이러한 차이는 김치맛과 발효에도 영향을 미치는 품질 요인이 될 수 있을 것으로 판단되며, 해양 심층수염을 이용하여 김치발효시 특성 변화에 대해 더 구체적인 연구가 필요하리라 사료된다.

• KSBB Journal
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• v.4 no.2
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• pp.191-196
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• 1989

Functional relationship between the Fermentation characteristics of Functional relationship between the Fermentation characteristics of S. cerevisiae SIV-89 and the fermentation time was investigated. According to the increase in the initial sugar cone. from 50g/L to 80 g/L, maximum specific growth rate and maximum specific alcohol production rate were increased until 0.35 and 1.98. But the two values were decreased with increase of initial sugar cone. in the region of more that 80 g/L. Maximum alcohol yield and biomass yield were 0.45 and 0.15 respectively. However those vlaue were found to be reduced with the argument of initial sugar concentration. Sugar conversion was decreased with sugar concentration. When the sugar concentration was more than 190 g/L, the conversion was dropped below 70%. The increase of alcohol concentration in the fermentation broth induced the phenomenon of decline of metabolism. In case of more than 80 g/L of alcohol conc., biomass growth and alcohol production were completely stopped regardless of remaining sugar concentration.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.430-435
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• 1987

A chitin-immobilized enzyme amyloglucosidase(AMG) and a bacterium Zymomonas mobilis were coentrapped in alginate gel beads. Ethanol production was performed in a packed bed column reactor in a simultaneous saccharification and fermentation(SSF) mode using liquefied sago starch as a substrate. It was found that this process eliminated product inhibition and reverse reaction of glucose enhancing the rate of saccharification and ethanol production. At a low dilution rate of D = 0.11 hr$^{-1}$, the steady-state ethanol concentration was 46.0g/$m\ell$ (96.8 % of theoretical yield). The maximum ethanol productivity was 17.7g/$m\ell$, h at D = 0.83 hr$^{-1}$ when the calculation was based on the total working volume. The continuous production of ethanol was maintained stably over 40 days without problems in this reactor system.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.326-332
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• 1983

Acorn wine was manufactured experimentally with koji inoculated the strain producing acorn tannin hydrolyzing enzyme in order to apply fungal tannase to food processing. Starch value of several Korean acorns was found to be 72.84 and the acorns were worthy of use as a carbohydrate food. Mixed koji was prepared by combination of rice and acorn powder at a ratio of 50to 50 and inoculation of Aspergillus oryzae producing amylase and Aspergillus sp. AN-11 producing tannase into the mixture in order to hydrolyze efficiently acorn tannin inhibiting alcohol fermentation in the medium, and then the mixed koji was used as a suitable koji to manufacture acorn wine. Acorn wine brewed with medium of the acorn powder treated with water and cooked and the mixed koji prepared was superior about two times to that brewed with medium of untreated acorn powder and general koji with respect to the rate of alcohol production and sugar fermentation during the 1st and 2nd brewing.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.265-271
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• 1991

In order to produce alcohol for the alternative energy from dried powder of Jerusalem artichoke was investigated with Kluyveromyces marxianus UCD(FST)55-82, which was reported to assimilate inulin. The optimal condition for the production of ethanol by K. marxianus was elucidated to be incubation temperature of $30^{\circ}C$, initial pH 5.44, agitation of 100 rpm, 1,000 ml of medium in a 2.5l-vessel, anaerobic state, and inoculation of 2.5%(v/v). Addition of antifoam A concentrate(si1icon polymer) of 0.01% and urea of 0.1% increased the concentration of ethanol effectively. The optimized condition showed ethanol concentration of 6.8%(v/v) in Jerusalem artichoke liquid medium, production yield of 91.91% and productivity of 2.71 g/l/hr during the first day and 0.71g ethanol/l/hr during four days of incubation.

• Applied Biological Chemistry
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• v.11
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• pp.95-100
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• 1969

마이야르반응(反應) 생성물(生成物)인 Premelanoidin 중(中) 주정발효(酒精醱酵)의 속도(速度)를 촉진(促進)하는 물질(物質)을 분리(分離)하기 위(爲)하여 양(陽)이온 교환수지를 이용(利用)하여 Premelanoidin을 fractionation하고 얻어진 각(各) fraction의 주정발효(酒精醱酵)의 활성(活性)여부를 시험(試驗)하였다. 양(湯)이온 교환수지로는 Dowex $50{\times}8$, 50-100을 사용(使用)하고 elution solvent로는 $2N-NH_4OH$ 용액(溶液)을 사용(使用)하였으며 얻어진 각(各) 5ml의 fraction은 냉동건조(冷凍乾操)해서 다시 본래(本來) 시료(試料)의 농도(濃度)(0.2N)로 희석하여 활성시험(活性試驗)에 사용(使用)하였다. Fractionation의 결과(結果)는 water filtrate 구(區)에 glucose, 5-HMF 및 소량(少量)의 갈색색소의 fraction을 얻었고 ammoniacal eluate 구(區)에 대부분(大部分)의 갈색색소와 glycine N-glycoside의 fraction을 얻을 수 있었다. 주정발효(酒精醱酵)의 활성(活性)은 glucose, 갈색색소 및 glycine-N-glycoside 구획에서 관찰할 수 있었으나 glucose 는 전(前) 실험(實驗)에서 활성(活性)이 없는 물질(物質)로 인정(認定)되었으며 본(本) 실험(實驗)에 나타난 활성(活性)은 Dowex 50에 의(依)한 fractionation 과정중 glucose 자체(自體)의 변질(變質)에 의(依)한 것으로 추측된다. 결국(結局) 활성물질(活性物質)이 존재(存在)하는 fraction은 Ammoniacal eluate 구(區)의 갈색색소 fraction과 glycine 및 N-glycoside를 함유하는 fraction이라고 인정(認定)된다.

• KSBB Journal
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• v.14 no.1
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• pp.114-118
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• 1999

In order to use a polysaccharide, curdlan, as a concrete admixture, we first developed a pilot-scale fermentation process for the mass production of curdlan. We also examined the rheological properties of curdlan, and tested how well the curdlan obtained in this work increased the segregational resistance of the cement slurry. Fermentation was performed in a 300-liter fermenter equipped with 3 disk-turbine impellers. Since curdlan production is stimulated under nitrogen-limiting conditions, the culture pH was shifted from the optimal pH for cell growth (pH 7.0) to the optimal pH for curdlan production (pH 5.5) at the onset of ammonium exhaustion. We obtained a curdlan production of 65 g/L in 120 hr batch cultivation of Agrobacterium species. The insoluble curdlan at the final stage of fermentation was readily harvested by centrifugation together with the cells. The freeze-dried sample contained 78% (w/w) of curdlan. The solubility and viscosity of the curdlan increased with the increase of the solution pH, which enhances the viscosity of concrete since the pH of concrete is extremely high (pH 13.0). Test results of the curdlan as a concrete admixture with cement slurry demonstrated that it prohibits the leakage of water. In conclusion, this work certifies and enlarges curdlan's industrial potential as a concrete admixture.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.226-230
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• 2007

In order to achieve high-level expression of interferon-${\alpha}1$ (IFN-${\alpha}1$) during fed-batch fermentation of recombinant E. coli, effects of oxygen supply and induction temperature on the expression of recombinant proteins were evaluated. Supplementation of oxygen and its transfer into cells is one of the most important parameters involved in the design and operation of mixing-sparging equipment for bioreactors. Generally, higher oxygen supply stimulates cell growth of aerobic microorganism and consequently the amount of products is increased. In this study, the optimum aeration strategy for the higher production of IFN-${\alpha}1$ during fed-batch fermentation of recombinant E. coli was surveyed. The growth of the cells was also monitored with four different concentrations of dissolved oxygen (DO; limiting, 20%, 35%, 50%) conditions. The DO was controlled by varying aeration rates of air and pure oxygen. Oxygen uptake rate (OUR) and specific oxygen uptake rate (SOUR) were evaluated and compared for the enhanced growth and induction of the cells and IFN-${\alpha}1$, respectively. We confirmed that increased DO by additional oxygen supply, up to 35%, can improve the production of IFN-${\alpha}1$ during the fermentation.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.1
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• pp.47-53
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• 2004

The characteristics of dough and the quality of white pan bread with 0∼1.5％ $\pi$-water were investigated. The fermentation volume and weight of the white pan bread with $\pi$-water (0.1％, 0.5％, 1.0％, 1.5％) was higher than that of the control. The volume of white pan bread with $\pi$-water (0.1％, 1.0％, 1.5％) was higher than that of the control. Color L value of crust with $\pi$-water increased from 34.98 to 36.38∼41.36 and increased from 34.32 to 34.90∼43.33 after 3 days. Color a value increased from 14.78 to 14.99∼16.75. The hardness of the white pan bread increased from 29011.0 g/㎤ to 18681.7∼43551.2 g/㎤ as the added amount of $\pi$-water increased. The overall acceptability score of white pan bread was the highest with 0.1％ $\pi$-water.