• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.62-69
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• 1999

Clostridium butyricum NCIB 9576 evolved hydrogen gas and produced various organic acids from glucose, lactose, starch, and glycerol. Total amount of hydrogen gas produced from 1 and 2% glucose were 630 and 950ml $H_2$/l-broth, respectively, for the first 24 hrs of incubation and the maximum hydrogen production rates were 42 and 94ml $H_2$/hr/1-broth, respectively. Teh initial pH 6.8 decreased to 4.2~4.5 during the first 12~16 hrs of fermentation when the pH was not controlled, resulting in ceasing the cell growth and hydrogen evolution and in degradation of 82 and 40% glucose after 24hrs of incubation from 1 and 2% glucose, respectively. When pH was controlled to 5.5, glucose was consumed completely and resulted in increasing hydrogen production approximately 38~50% compared to the experiments without the pH control. C. butyricum NCIB 9576 produced hydrogen gas approximately 644, 1,700 and 3,080 ml $H_2$/l-broth with 0.5, 1 and 2% lactose, respectively and the maximum hydrogen production rates were 41, 141 and 179ml $H_2$/hr/l-broth, respectively. All of the lactose added was degraded completely during fermentation even though pH was not controlled. C. butyricum NCIB 9576 produced 183 and 709ml $H_2$/l-broth with 0.1 and 0.5% starch for 48 hrs, respectively, when pH was not controlled. The maximum rates of hydrogen gas production were 43 and 186ml $H_2$/l-broth, respectively and 80~100% of starch added was fermented. Approximately 107ml $H_2$/l-broth was produced using 1% glycerol by C. butyricum NCIB 9576 and the pH was maintained higher than 6.1 during fermentation without pH control. The degradation of glucose, lactose, starch and glycerol by C. butyricum NCIB 9576 were affected by the pH of fermentation broth and the organic acids released during fermentation. The pH of feremtntation broth dropped to 4.2~4.6 after 12~14 hrs incubation when glucose was used as a substrate while pHs were maintained above pH 5 under the same experimental conditions when lactose, starch and glycerol were used. The organic solvents and acids produced during glucose fermentation were mainly ethanol, butyrate, acetate and a little of propionate, while butyrate was the main organic acids during the lactose, starch, and glycerol fermentation by C. butyricum NCIB 9576.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.588-596
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• 1992

The fermentation characteristics of ethanol production by the use of immobilized Zymomonas mobilis KCTC 1534 cells were investigated in terms of formation factors such as substrate and product concentration. In batch fermentation, the maximum values of specific ethanol productivity, specific substrate uptake rate, ethanol yield, and glucose conversion rate were $29.14g/{\ell}{\cdot}h$, $60.24g/{\ell}{\cdot}h$, 0.48g/g, and 98.4%, respectively, with 17% glucose medium, and its ethanol productivity was $2.91g/{\ell}{\cdot}h$ in the case of 25 hour fermentation time. Repeated batch fermentation was possible for 30 days with 2.24-$2.94g/{\ell}{\cdot}h$ ethanol productivity. In semicontinuous fermentation, the maximum ethanol productivity was shown to be $15.7g/{\ell}{\cdot}h$ at $0.36h^{-1}$ effective dilution rate with 17% glucose concentration. In this case, ethanol yield coefficient and glucose conversion rate were 0.39 g/g, 64.7%, respectively.

• Toxicological Research
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• v.28 no.2
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• pp.117-122
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• 2012

Flavonoids, which form a major component in Houttuynia cordata Thunb., display a wide range of pharmacological activities. The expression of plant flavonoids is partly regulated by fermentation. Therefore, we studied the effects of fermentation on H. cordata in order to identify the strains present during the fermentation process, and to determine whether fermented H. cordata could be used as a probiotic. Our results showed that all 6 of the bacterial strains isolated from fermented H. cordata (FHC) belonged to the genus Bacillus. As expected, fermenting H cordata also increased the flavonoid content as increases were observed in the levels of rutin, quercitrin, and quercetin. To test the effects of fermentation, we treated LPS-stimulated RAW264.7 cells with non-fermented H. cordata extracts (HCE) or FHC extracts (FHCE). Compared to the HCE-treated cells, the FHCE-treated cells showed increased viability. No cytotoxic effects were detected in the FHCE-treated groups in the 2 cell lines used in the study, namely, RAW264.7 and RBL-2H3. FHCE-treated HepG2 cells showed decreased growth, compared to HCE-treated HepG2 cells. These results indicate that the fermented H. cordata predominantly contained Bacillus strains. Furthermore, FHCE are able to prevent LPS-induced inflammatory effects and inhibit the growth of HepG2 cells.

• KSBB Journal
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• v.14 no.5
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• pp.628-632
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• 1999

Optimization of the medium and fermentation conditions for erythritol production has been studied. We have found that the optimal carbon source was glucose at the concentration of 400 g/L. The optimal temperature was 3$0^{\circ}C$ with excessive aeration. Improved erythritol productivity was achieved by reducing the yeast extract from 5 g/L to 3g/L while adding 2.7 g/L urea, 1.79g/L $K_2HPO_4, and 0.18g/L MgSO$_4$. 7$H_2O. The erythritol productivity increased from 0.747 g/L/h to 1.071 g/L/h and the yield increased from 31.4% to 45.2%. The byproduct glycerol was reduced from 96.6g/L to 45.7g/L as well. We have performed 5L fermentation with and without the pH control. The erythritol productivity with the pH control was about 30% lower than that without pH control. Excessive foaming of 5L fermentation has been observed during fermentation.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.46-52
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• 1996

Effective method for the preparation of Dongchimi juice was developed by addition of NaCi, sucrose and bydrolytic enzymes before fermentation and addition on Dongchimi juice during fermentation. The radish was ground and suspended in water(1:1, w/v) with addition of spices(garlic, green onion and ginger) followed by fermentation at $25^{\circ}C$. The addition of 2% NaCi and 0.5~2.0% sucrose resulted in significant increase of solid content and it was also improved by the addition of polysaccharide hydrolyzing enzyme during fermentation. When the fermented juices of pH 5.4 of 4.4 were added by 15% of total weight before(pH 5.4 juice)and during (pH 4.4 juice) fermentation, a significant increase in solid content after 24hrs of fermentation was resulted. The combined method of addition of 2% NaCI, 1.0% sucrode, 0.1% Viscozyme and 10% of fermented juice of pH 5.4 and 4.$ before and during fermentation improved solid content, reducing sugar, color and showed little effect on viscosity. The organoleptic characteristics were also improved by the combined method.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.726-732
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• 1994

Development of an effective method for the preparation of dongchimi juice was investigated by addition of NaCl, sucrose and hydrolytic enzymes before fermentation and addition of dongchimi juice during fermentation. The Chinese radish was ground and suspended in water (1:1, w/v) with addition of spices of garlic, green onion and ginger followed by fermentation at $25^{\circ}C$. Increase in NaCl concentration of brinning solution from 1.0 to 5.0% resulted in a significant decrease in the rates of pH decrease and acidity increase. The sugar addition resulted in a faster changes of them, particulary after 24 hours at $25^{\circ}C$. The fermentation rate was also greatly improved by enzymatic hydrolysis with using viscozyme, a commercial polysaccharides hydrolyzing enzyme, before fermentation. When the fermented juices of two stage (pH 5.4 and pH 4.4) were added up to 15% before (pH 5.4 juice) and during (pH 4.4 juice) fermentation, the initial and second stage of fermentation were significantly improved. Therefore a method of addition of sugar, hydrolytic enzymes and dongchimi juice before or during fermentation was suggested for dongchimi juice preparation.

• Journal of Life Science
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• v.18 no.4
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• pp.556-564
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• 2008

Response surface methodology was used to monitor the optimization of fermentation conditions for red ginseng wine. A central composite design was applied to investigate the effects of independent variables, fermentation temperature ($X_1$), fermentation time ($X_2$) and initial pH ($X_3$) on dependent variables, physicochemical characteristics and effective ingredients. Alcohol and total sugar content were significantly affected both by fermentation temperature and time. Crude saponin content was greatly affected by fermentation time, and pH was significantly affected by initial pH. Fermentation time and initial pH had a greater effect on ginsenoside content than fermentation temperature. Ginsenoside content increased along with fermentation time and initial pH. We elicited a regression formula for each variable, and superimposed the total optimum points of fermentation conditions for physicochemical characteristics and the effective constituents. The predicted values at the optimum fermentation conditions were at $21{\sim}27^{\circ}C$ for $15{\sim}20$ day in initial pH $4.6{\sim}5.2$.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.30-36
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• 2002

To use overproduction muskmelon effectively, muskmelon vinegar was prepared by two stage fermentations of alcohol and acetic acid. In the alcohol fermentation using muskmelon, alcohol content showed maximum value (7.47%) in $17.83^{\circ}Brix$ of initial sugar concentration and 82.65 h of fermentation time. Acetic acid content in alcohol fermentation revealed minimum value (0.46%) in $12.17^{\circ}Brix$ of initial sugar concentration and 60.56 h of fermentation time. The fermentation conditions for minimum residual sugar were $10.02^{\circ}Brix$ of initial sugar concentration and 105.61 h of fermentation time. The optimum conditions predicted for each corresponding physical properties of acetic acid fermentation were 200 rpm (agitation rate), 250 h (fermentation time) in acetic content and 200 rpm, 150 h in residual alcohol content.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.293-300
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• 2015

We sought to extend the shelf-life of Alaska pollack Theragra chalcogramma sikhae while maintaining quality. We compared the chemical, microbiological, and organoleptic characteristics of sikhae prepared under four different conditions. Control fish were fermented at ambient temperature ($21{\pm}2^{\circ}C$); other samples were stored at $5^{\circ}C$ after fermentation at ambient temperature for 36 h (A1), 60 h (A2), and 84 h (A3). Volatile basic nitrogen and amino-nitrogen levels, and total acidity increased with fermentation time in all samples, but the pH fell, attaining a relatively lower level in the control than in other samples. Over 90% of all viable cells were lactic acid-producing bacteria; this proportion did not change significantly during fermentation. In terms of texture, only hardness was affected by fermentation. The hardness of the control fell more rapidly than did that of the other samples. In terms of sensory evaluation (the acceptance test and quantitative descriptive analysis [QDA]), A2 was superior to other samples after fermentation for different times; A2 maintained limited salability (6 points on the relevant index) for up to 17 days of storage.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.246-251
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• 1999

To extend the storage period and to inhibit contamination of Kimchi by Escherichia coli, conditions of Kimchi brining and effects of the fermentation starter, halophilic Lactobacillus HL-48 were investigated. Optimum brining condition for Kimchi was accomplished in 15% NaCl and at pH2.5-3.0 adjusted by lactic acid. Starter-treated Kimchi showed pH 4.2 after 18hr fermentation, while the pH of starter-untreated Kimchi resulted in 3.3. After 36hr fermentation, the number of E. coli in starter-treated Kimchi was found clearly to decrease and not detected macroscopically, but contamination of E. coli (5.3$\times$103CFU/ml) was observed in starter-untreated sample. Organic acids in Kimchi contained organic acids such as oxalic acid, citric acid, malic acid and lactic acid. among ther, lactic acid content was remarkably high in the early fermentation stages. However, from 24hr fermentation, lactic acid content of starter-untreated Kimchi was higher than that of starter-treated Kimchi.