• Transactions of the Korean hydrogen and new energy society
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• v.13 no.4
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• pp.321-329
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• 2002

Clostridium butyricum, Lactobacillus amylophillus, Lactobacillus amylovorus, Lactobacillus acidophillus, AI-9 produced hydrogen and /or organic acids using glucose, lactose and starch at the anaerobic culture conditions. Cl. butyricum NCIB 9576 evolved 1,700 ml H2/L-culture broth and accumulated butyric acid, acetic acid, propionic acid and ethanol in its culture broth when lactose was used as a carbon source during 24 hrs of fermentation. L. amylovorus ATCC 33620 accumulated lactic and acetic acids and some reducing sugars when starch was used as a carbon source without hydrogen production. Instead of starch as a carbon source, L. amylovorus ATCC 33620 produced lactic acid from algal biomass during fermentation and the acid-heat or freeze-thaw pretreatment of algal biomass accelerate the lactic acid fermentation.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.377-389
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• 2013

Gamma-amino butyric acid (GABA) is a kind of pharmacological and biological component and its application is wide and useful in Korea specially, becoming aging society in the near feature. GABA is request special dose for the purposed biological effect but the production of concentrated GABA is very difficult due to low concentration of glutamic acid existed in the fermentation broth. To increase GABA concentrate using fermentation technology, high content of glutamic acid is required. For this reason, various strains which have the glutamic acid decarboxylase (GAD) and can convert glutamic acid to GABA, were isolated from various fermented foods. Most of GABA producing strains are lactic acid bacteria isolated from kimchi, especially added monosodium glutamate (MSG) as a taste enhancer. Optimizing the formulation of culture media and the culture condition, GABA conversion yield and amounts were increased. Finally GABA concentration of fermentation broth in batch or fed batch fermentation reached 660 mM or 1000 mM, respectively. Furthermore formulation of culture media for GABA production developed commercially. Many studies about GABA-rich product have been continued, so GABA-rich kimchi, cheese, yogurt, black raspberry juice and tomato juices has been also developed. In Korea many biological effects of GABA are evaluated recently and GABA will be expected to be used in multipurpose.

• Culinary science and hospitality research
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• v.13 no.1 s.32
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• pp.55-61
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• 2007

This study was carried out to evaluate the growth characteristics of Lactobacillus acidophilus KCCM 32820 and Propionibacterium freudenreichii KCCM 31227 and the production of propionic and acetic acids in 5% and 10% whey broth by mixed culture of L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227. Exponential phase of L. acidophilus KCCM 32820 was in the range of $6\sim12$ hrs and P. freudenreichii KCCM 31227 was in the range of $36\sim108$ hrs. In the mixed culture, production of propionic acid was shown to be greater value in the 10% whey broth than in the 5% whey broth and to be greater value in the low temperature for a long time than in sterilization by autoclave. Maximum production of propionic acid was 8.88 mg/mL in the 10% whey broth fermented at 120hrs. Production of acetic acid was revealed to be greater value in the 10% whey broth than in the 5% whey broth. The production quantity ratio of propionic acid to acetic acid was shown between $2:1\sim3:1$ during the fermentation process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.981-985
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• 2003

The changes of component through simultaneous production of bacterial cellulose and vinegars by G. persimmonis KJ145$^{T}$ were examined. As a results, pH was decreased to 3.22 at 8 days of fermentation and total acidity showed 4.66 which was the highest at the 8 days of fermentation. Brix didn't show any changes during the fermentation period. Free sugars of fermentation broth were consist of fructose, glucose and sucrose. The fructose concentration of fermentation broth was maintained highly during fermentation period (until the final 10 days) without a remarkable decrease. The cell growth of G. persimmonis KJ145$^{T}$ was very rapidly increased from the 2 days of fermentation and increased most at the 4 days of fermentation. The productivity of bacterial cellulose was increased in proportion to the fermentation period. Malic acid, succinic acid and oxalic acid were detected as a organic acid of vinegar. The concentration of acetic acid was rapidly increased from the 2 days and reached highest concentration at 8 days. In conclusion, the results indicated that the 8 days was the optimal fermentation period to produce the bacterial cellulose and vinegar by G. persimmonis KJ145$^{T}$ simultaneously.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.162-168
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• 2001

For lactic acid fermentation of chestnut broth,10 strains of bacteria were isolated from human feces and commercial yogurt,6 of which were identified to be Bifidobacterium and the rest isolated from Acidities of the chestnut broths fermented by these strains were lower than yogurt, but more than two times higher than yogurts made from seeds or vegetables including soy milk. To stimulate acidity of the fermented broths, addition of yeast extract and tryptone peptone were the most effective at the concentration of 0.2 and 0.4%, respectively, while glucose addition above 0.5% up to 8% did not increased the acid production except a few strains of Lactoba- Cillus. Among the tested fruits and vegetables, carrot juice supplementation was the most effective in acid produc- tion by most of the tested strains. Saccharification of chestnut broth by hydrolyzing process greatly increased the acid production at 25% of cooked chestnut. However, compared to the results from the 8% of unhydrolyzed chest- nut, the net increase in acid production by hydrolysis was not much stimulative.

• KSBB Journal
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• v.10 no.4
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• pp.370-373
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• 1995

The major by-products in ethanol fermentation by Saccharomyces cerevisiae were glycerol, acetaldehyde, acetic acid, lactic acid, and formic acid. The effects of these by-products on the cell growth and ethanol production were studied. By adding acetaldehyde or acetic acid in the fermentation broth, the cell growth decreased while the ethanol production increased. But glycerol and lactic acid had nearly no effects on the cell growth and the ethanol production. Acetic acid and acetaldehyde inhibited the cell growth by diminishing the growth rate as well as by prolonging the lag phase. The ethanol yield increased with the elevation of concentrations of acetic acid and acetaldehyde in the fermentation broth. The maximum ethanol yield was obtained for $3g/\ell$ acetic acid and $2g/\ell$ acetaldehyde, respectively.

• Membrane Journal
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• v.23 no.4
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• pp.304-311
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• 2013

In fermentation-separation processes, nanofiltration membrane processes can be used to separate organic acid and other byproducts such as sugars and proteins. In this study, new nanofiltration membranes were prepared to improve organic acid permeability during the separation processes of fermentation broth. Positively charged nanofiltration membrane was introduced to reduce lactic acid rejection by electrostatic attraction between lactic acid and nanofiltration membrane. Newly fabricated nanofiltration membranes were prepared by grafting cationic polyelectrolyte, PEI, on membrane surface. Thenanofiltration membranes showed positively charged surface potential. As a result, lactic acid rejection was remarkably reduced while the rejection of glucose was not changed significantly.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.47-53
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• 2018

Recovery of lactic acid from fermentation broth using chemical precipitation was investigated with various chemicals. Effects of chemical types, mixing speeds, settling duration, and solvent addition were evaluated to improve the recovery rates of lactic acid. Overall, recovery efficiencies increased as the dosage of chemicals increased. Recovery rate of lactic acid by CaO was higher than those of $Ca(OH)_2$ and $CaCO_3$. Recovery of lactic acid increased by 48% under the optimized reaction conditions which included a mixing speed at 180 rpm, a settling duration of 24 h, and addition of ethanol at 25%(v/v). Practical application needs to consider types and concentrations of other organic acids as well as lactic acid. Based upon the results of fluorescence excitation emission matrix (FEEM), size exclusion chromatography (SEC), characteristics of recovered lactic acid were same as that in the fermentation broth.

• YAKHAK HOEJI
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• v.31 no.6
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• pp.402-404
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• 1987

Fermentation processes have been employed to produce 17-ketosteroids from sterol with chelator of Fe$^{2+}$ such as $\alpha$, ${\alpha}'$-dipyriyl. To analyze the products of sterol fermentation, we developed a simple TLC method without interference of the chelator $\alpha$, ${\alpha}'$-dipyridyl, using Ag$^+$ band on TLC plate.

• Journal of Ginseng Research
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• v.6 no.2
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• pp.131-137
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• 1982

The effect of red ginseng residue on the several enzyme activities of the koji and alcohol fermentation were investigated. The koji showed maximum values of amylase and cellulase activity when it was prepared by 30% red ginseng residue and 70% wheat bran, and of protease activity when it was prepared by 40% red ginseng residue and 60% wheat bran-${\alpha}$ amylase activity of the koji during its fermentation was increased rapidly until 4 days and there after it was increased slowly, but ${\beta}$-amylase was rapidly increased after 3 days fermentation. During the preparation of the koji, the acidic, neutral protease and cellulase activities showed the maximum value after 3 days fermentation and the alkaline protease showed the maximum value within 4-6 days fermentation. On the otherhand, fermented broth, containing 6%(v/v) alcohol, could be obtained when the substrate was saccharified by the koji, based on 25% red ginseng residue and 75% wheat bran, prior to alcohol fermentation.