• Proceedings of the Korean Society for Applied Microbiology Conference
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• 한국미생물생명공학회 1979년도 추계학술대회 심포지움
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• pp.246.1-246
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• 1979

A glucose-limited “pH-stat” continuous culture study of Lactobacillus bulgaricus NLS-4 in an anaerobic condition showed the marked effects of environmental pH on end products, fermentation blances and bioenergetic aspects of the organism. Lactic acid was the major end product of fermentation with minor products, such as acetic acid, formic acid and ethanol throughout the pH range tested. In acidic conditions below pH 6.5, a typi-cal pattern of homofermentation was revealed whereas in alkaline conditions, the metabolic pattern was changed from homofermentation to heterofermentation and led to acquire much energy. This metabolic change was likely due to the pH-dependent lactate dehydrogenase activity. Molar growth yields (Yglc=35.5-44.4) and YATP, $18.5\pm2.5$ in average which was 80％ higher than the value ever postulated seemed to be accounted for less requirement of maintenance energy of the organism in the culture conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• 제11권1호
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• pp.53-59
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• 1991

This experiment was conducted to investigate the effects of propionic acid and wilting on fermentation quality of Italian ryegrass silage. Grass material was wilted for a day before ensiling and propionic acid(0. 0, 0. 2. 0. 5 and 0.8 7~ of fresh matter) was applicated at ensiling time. Chemical composition, fermentation acids, pH, microbial population and distribution of the nitrogen contents were evaluated. The results obtained are summarized as follows: 1. The contents of dry matter and water soluble carbohydrate in the silage were increased by wilting, and crude fibre, NDF and ADF were decreased with increasing propionic acid levels. 2. The pH values of the silage increased by increasing DM content, but decreased with increasing propionic acid levels. Lactic acid content lowed in wilted silage, and acetic acid and butyric acid formation were decreased with increasing propionic acid levels. 3. Total nitrogen content in the silage was i n ~ r e a s e d ( ~ < . 05) by addition of propionic acid and wilting, and was the highest in the prewilting-0.8 Q propionic acid applicated silage. The production of NHBN was decreased with propionic acid and was the lowest in the 0.8 % treated silage. 4. The number of total bacteria and yeasts were estimated $10^6~10^7$, $10^2~10^3$ respectively. Moulds number were decreased with increasing propionic acid levels.

• Journal of the Korean Society of Food Culture
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• 제30권3호
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• pp.377-386
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• 2015

The purpose of this research was to appraise physicochemical properties by utilizing different Mit-sool, Juk, Seolgi-tteok, and Godubap, to produce traditional liquor. In all experimental plots, pH and amino acidity tended to increase with duration of fermentation. Titratable acidity displayed a very high number on the second day but then tended to decrease as fermentation progressed. Sugar contents were highest on the fourth day and tended to decrease with time. Alcohol content increased sharply at the initial stage of fermentation and increased gradually. On the 15th day, traditional liquor made with Godubap recorded the highest alcohol content. Common free sugar components were glucose and sorbitol. Common free organic acid components were lactic, succinic, citric, tartaric, malic, and acetic acids. Volatile flavor compounds were six alcohols, five esters, three aldehydes, and two ketones. Regarding overall acceptability in the sensory evaluation, traditional liquor using Seolgi-tteok as Mit-sool scored the highest. Overall, even though different types of Mit-sool had different physicochemical properties, there were no significant differences in volatile flavor compounds or sensory evaluation scores.

• Food Science and Preservation
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• 제11권2호
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• pp.240-245
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• 2004

Chungju(Sambaekju) supplemented with dried persimmon and cordyceps sinensis was prepared and its characteristics were estimated during the brewing. Reducing sugar contents was decreased, ethanol contents was increased in the during fermentation, the final ethanol contents in the first, second and third mash were 5.8%, 11.4% and 16.5%, respectively. Total acidity and amino acidity were increased in the during fermentation. The major organic acid was latic acid, acetic acid, malic acid and succinic acid were a little, and citric acid and tartaric acid were not detected. L-proline(1151.7 mg%) was major in free amino acid. the contents of total and essential amino acid were 11.19% and 217.70 ppm, respectively.

• Journal of Ginseng Research
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• 제20권3호
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• pp.307-317
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• 1996

This study was undertaken to examine the effects of fresh ginseng addition on the chemical and sensory properties of dongchimi juice fermented under various conditions. The contents of free sugars in dongchimi juice during fermentation increased at the initial stage, but decreased at the palatable stage and then increased again thereafter. Free sugars were higher in dongchlml juice with 4% of ginseng addition than with Soye ginseng and without ginseng addition. Analyses of organic acid contents showed that all three groups contained relatively high amounts of citric, lactic and malic acids. It was also found that, as fermentation progressed, the amounts of tactic and acetic acids in- creased, while that of malic acid decreased at the palatable stage and increased again thereafter. Total saponins were highest in dongchimi juice fermented at 4$^{\circ}C$ with 4% of ginseng addition and panax atrlol ginsenosldes were found more than panaxadiol ginsenosides in dongchimi juice The results of sensory evaluation revealed that dongchimi juice prepared with the addition of $4^{\circ}C$ and 4% ginseng was lower in sour taste and moldy off flavor than the control, thus scoring high In total acceptability. Dongchimi juice with 4% of ginseng addition was best in most sensory characteristics.

• Journal of Dairy Science and Biotechnology
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• 제40권1호
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• pp.23-34
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• 2022

In this study, to determine the importance of lactic acid bacteria (LAB) in Kombucha fermentation, biological functions, such as organic acid production and anti-inflammatory and antibacterial activities, of Kombucha, with or without LAB inoculation, were evaluated. Lactobacillus paracasei DK215, Saccharomyces cerevisiae C3, and Acetobacter pasteurianus P2 were selected as the inoculants. Organic acids were measured every 3 days from the end of fermentation using HPLC; the organic acid content of LAB-inoculated Kombucha was relatively high. Samples with or without LAB inoculation showed high antibacterial activity against Escherichia coli. The MTT assay results indicated no significant difference in concentration difference and cell death. In the NO production test, compared with the uninoculated Kombucha sample, the LAB-inoculated Kombucha sample exhibited a value similar to that of the group without LPS treatment. The levels of cytokine (IL-1α, IL-6, TNF-α) production were significantly lower than those of the LPS(+) group, indicating the anti-inflammatory activity potential of the Kombucha sample. This improvement in the biological function of the LAB-inoculated Kombucha further verifies the value of LAB in the fermented food and beverage industry.

• Microbiology and Biotechnology Letters
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• 제1권2호
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• pp.105-113
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• 1973

The effect of biotin and biotin vitamer on the fermentative production of L-glutamic acid (L-GA) by Brevibacterium flavum was studied. And results were as follows. 1) L-GA production in the medium containing 10％ Glucose was the best at the concentration of Biotin 5${\gamma}$/l, Desthiobiotin 5${\gamma}$/1, and 7,8-Diaminopelargonic acid 10${\gamma}$/1, respectively. 2) In the experiment using the Glucose-Acetate mixed media derided into four parts, considerable amounts of cell growth and L-GA production were observed in the mixed medium containing 2％ Glucose-Acetate. 3) In the cases of using the media containing methanol, ethanol, ethylacetate, acetic acid (free acetate), Na-acetate:NH$_4$-acetate=2 : 1, the production of L-GA were in decreasing order as follows; Na-Acetate:NH-Acetate=2 : 1> Acetic acid (free acetate)> Ethylacetate> Ethanol＞ Methanol. 4) When biotin vitamers as growth factors were added in the medium containing Glucose or Acetate as the source of carbon, the substitution effect of Desthiobiotin was almost the same, 7,8-Diaminopelargonic acid 3 or 4 times stronger, and Bisnorbiotin has no substitution effect, compared with Biotin.

• KSBB Journal
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• 제8권4호
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• pp.382-389
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• 1993

In order to elucidate the effect of acetate ion on the growth of Escherichia coli, flask and fermentor cultures were performed using M9 and LB media. Acetic acid was secreted at a higher rate under the conditions of high glucose concentration as well as of richer medium, i. e., LB broth. The pH in flask culture could not be controlled as i fermentor and pH decreased with the formation of acetic acid. The inhibition effect of acetic acid was pronounced at a lower pH, and the effective inhibitory concentrations of acetic acid were 2.0g/l for LB flask culture, 4.0g/l for M9 flask culture, and 8.0g/l for M9 fermentor culture. Dialysis flask culture was designed to slowly provide E coli cells with glucose. Solid LB agar was layered under LB liquid medium with the variation of agar concentration and solid volume, The increase in the solid portion in the total volume(agar＋liquid) resulted in the increase of the final cell concentration. This can be ascribed to the fact that the larger solid phase behaves like a larger reservoir for glucose and controls the growth of E. coli with a controlled rate.

• Analytical Science and Technology
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• 제20권3호
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• pp.204-212
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• 2007

The study was carried out to investigate the ratio of ethanol to n-propanol in blood and urine specimens, and developed a method for distinguishing ingested ethanol from artifactual ethanol in urine samples. In case of no urinary ethanol was detected, the ratio of ethanol to n-propanol concentration was about 12~20 times higher than those of blood. Therefore, it might be a good method to determine whether the detected ethanol is from drinking or from microbial fermentation. During the metabolism of ethanol, the levels of the metabolite of serotonin (5-hydroxytryptamine, 5-HT) and 5-hydroxyindole-3-acetic acid (5-HIAA) were decreased, while 5-hydroxytryptophol (5-HTOL) was increased. The levels of 5-HTOL/5-HIAA in urine samples of drinking suspects were greater than 1, in that of no drinking suspects were less than 1.

• Food Science and Preservation
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• 제24권2호
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• pp.254-265
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• 2017

For the production of ${\gamma}-aminobutyric$ acid (GABA) contents increased Seomaeyaksuk fermentant, 0, 0.25, 0.5 and 1.0% of monosodium galutamate (MSG) was added in Seomaeyaksuk water extract 15% contained Sikhye and inoculated with Lactobacillus brevis (KI271266). Physicochemical properties were sampling and analyzed at each 1 day during 3 days fermentation. Goes on fermentation periods, the turbidity was gradually reduced, but lightness and the yellowness was increased, redness was decreased. Soluble solid was also decreased. The reducing sugars content were also decreased during fermentation. pH was 4.65-4.83 before fermentation but it was lower 3.15-3.68 after three days fermentation. The GABA contents increased by fermentation periods and it was the highest in MSG 1.0% added sample (354.38 mg/L). Fructose, glucose and sucrose contents were 50-67% decreased at three days fermentation than before fermentation. Among the organic acids, propionic acid, oxalic acid, citric acid and fumaric acid contents were decreased and lactic acid, acetic acid and succinic acid were increased during fermentation periods. Contents of total polyphenol and DPPH radical scavenging activity were the highest in MSG 0.5% added sample. From these results, we confirmed that increasing of GABA content when the manufacturing of Seomaeyaksuk lactic acid fermentation product, is possibile by addition of MSG without affecting physicochemical characteristics.