• Korean Journal of Microbiology
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• v.37 no.4
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• pp.312-316
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• 2001

To improve the ethanol fermentability, four Saccharomyces yeast strains with efficient ethanol fermentability were subjected to rare-mating and protoplast fusion. Using these 4 strains, 5 different combinations of mating-pair or fusion-pair were constructed and their hybrids or fusants were obtained. From the statistical analysis of the results of the ethanol fermentation by the hybrids of the different mating-pair or fusion-pair, no difference was found in ethanol production, but [S. kluveri $khl{\times}S$ cerevisiae cp3] pair was shown to be the best combination which can produce high cell-viability. In fact, the clone No. 3 of the [S. kluveri $khl{\times}S$ cerevisiae cp3] pair was selected as the best strain which produced ethanol of 10.11% (w/v) or 12.81% (v/v) from 25% (w/v) glucose at $33^{\circ}C$ for 3 days with the residual sugar of 3.53% (w/v), viability of 62.65%, fermentation efficiency of 92.2%.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.90-94
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• 1984

We deduced a possible metabolic pathway of L-malate in a malo-alcoholic yeast, Schizosaccharomyces japonicus var. japonicus St-3. The malic enzyme (EC 1.1.1.40) prepared from the microorganism was about four times as active as that of malate dehydrogenase (EC 1.1.1.37). And Km values of malic enzyme and malate dehydrogenase for malate were found to be 3.125 mM and 4.761 mM, respectively, which referred to the fact that the affinity of malic enzyme for the substrate was greater than that of malate dehydrogenase. We also found that pyruvate was produced with disappearing malate in malo-alcoholic fermentation, and that the addition of $Mn^{2+}$ activated malic enzyme activity. Based on these results obtained we have deduced a main pathway of malate${\rightarrow}$pyruvate${\rightarrow}$acetaldehyde${\rightarrow}$ethanol for the utilization of L-malate by this malo-alcoholic yeast strain.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.329-337
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• 1985

A potent mold strain was selected to digest raw starch, which was classified as a strain of Rhizopus of zoe. Its amylase production was maximized when grown on wheatbran media for 3 days at 3$0^{\circ}C$ and initial pH 4. The crude enzyme was tested for ethanol fermentation by yeast, Saccharomyces cerevisiae IFO 7026, on various starchymaterials and the ethanol production after 4 days was: 9.4％ from rice powder, 9％ from corn powder, 8.1％ from sweet potato powder, and 5.4％ from potato powder, respectively.

• Food Science and Preservation
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• v.17 no.5
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• pp.608-615
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• 2010

We investigated the effect of grape-must temperature ($50^{\circ}C$, $60^{\circ}C$, and $70^{\circ}C$) on wine quality. We used Muscat Bailey A (MBA) grapes; these are often used in wine making in Korea. The numbers of viable bacteria, yeasts and molds in grape-must decreased with an increase in temperature. Polyphenol oxidase activities in grape-must were reduced at high temperatures. Redness; and, total anthocyanin, polyphenol, and tannin contents of MBA grape wine were higher after heating at $70^{\circ}C$ than after use of lower temperatures. Antioxidant activity was also enhanced after exposure to high temperatures, which may be attributable to the presence of increased levels of polyphenolic compounds in the grape-must. Thus, the heat treatment to prepare grape-must before wine fermentation greatly affects wine quality.

• Food Science and Preservation
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• v.18 no.4
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• pp.604-611
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• 2011

Several wild yeasts were isolated from Korean grape varieties before and during spontaneous fermentation. Among them, four strains were isolated based on the alcohol content and flavor production in wine after fermentation of apple juice. In this study, the four yeast strains were identified and characterized. PCR-restriction fragment length polymorphism analysis of ITS I-5.8S-ITS II region with restriction endonuclease Hae III and Hinf I resulted in that all the strains showed a typical pattern of Saccharomyces cerevisiae. Pulse field gel electrophoresis showed three different chromosome patterns with a same band between strains SS89 and SS812. When ITS I-5.8S-ITS II sequences of the four strains were compared with one another, they were similar to those of Saccharomyces cerevisiae CBS 4054 type strain. Identity of the sequences was higher than 97% with those of the type strain. Phylogenetic analysis showed based on the sequences showed they were genetically closed to the type strain. The four identified strains were tested in a medium containing 200 ppm potassium metabisulfite, and the MM10 and WW108 inhibition rates resulted at up to 24 h. The four strains were tested at an incubation temperature of $30^{\circ}C$. The 30% sugar concentration in the medium (w/v) showed the highest growth in 36 h, especially in the case of SS89, which was close to growth 40. The four strains were tested in an 8% ethanol medium (v/v). Alcohol tolerance was initially kept in the incubation process. The strains began to adapt, however, to the exceeded resistance. The four strains showed the lowest inhibition rate at 24 h.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1854-1859
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• 2010

Three kinds of Korean traditional Meju were selected and the counts of microorganisms in these Meju were determined. The counts of total aerobic bacteria, lactic acid bacteria and yeasts and molds were 107~108, 106~108 and 107~108 cfu/g, respectively in three Meju and lactic acid bacteria were important microorganisms in the fermentation of Meju. Therefore, we isolated three kinds of dominant lactic acid bacteria from these Meju. They were identified as Leuconostoc mesenteroides (98%, Lm-SMm), Lactobacillus plantarum (99%, Lp-SMm) and Lactococcus lactis (98%, Ll-GAm). Then, enzyme activities and physiological functionalities of three lactic acid bacteria were investigated. Protease, lipase and $\alpha$-amylase activities were detected in three lactic acid bacteria, Ll-GAm showed relatively higher activities than other two lactic acid bacteria. Lm-SMm, Lp-SMm and Ll-GAm showed 45, 48 and 60% of antioxidative activity to 1,1-diphenyl-2-picryhydrazyl (DPPH), and exhibited 45, 67 and 70% of inhibitory effects in HT-29 human colon cancer cells, respectively. These results indicate that three lactic acid bacteria isolated from traditional Meju, especially Ll-GAm are applicable to Meju preparation for soybean paste industry.

• KSBB Journal
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• v.4 no.1
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• pp.21-30
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• 1989

Lauryl alcohol was used as extracting solvent of ethanol, and its toxicity on the free cells or immobilized cells was tested. To increase ethanol productivity, extractive fermentation method combined with ethanol fermentation and ethanol recovery was applied to the immobilized batch and continuous fermenter. As the concentration of LaOH was increased, the lag phase became longer, but specific growth rate did not change greatly. And a cell entrapment technique could protect the yeast cells against both substrate inhibition and solvent toxicity. When the glucose concentration was 400 g/l and the LaOH/fermentation medium ratio was 4, total ethanol productivity increased with the enhancement of LaOH volume, and maximum productivity was 2.75 g/l.hr in the immobilized batch fermentation.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.538-545
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• 2020

Kimchi is a widely consumed traditional Korean food, and its probiotic properties have received great attention. In this study, changes in the quality characteristics of fermentation broths obtained from two types of Chinese cabbage kimchi (red with red pepper and white without red pepper) were assessed after the administration of blue light emitting diode (BLED) irradiation at 4℃; characteristics assessed included acidity, chromaticity, antioxidant activity, and growth modulation of isolated microorganisms. The pH of the white kimchi (WK) broth decreased with time; the decrease was delayed significantly under BLED irradiation (p<0.05). BLED irradiation decreased the L (lightness) and b (yellowness) values and increased a (redness) in WK, whereas the a and b values of the red kimchi (RK) broth increased with BLED irradiation. Growth stimulation of lactic acid bacteria by BLED irradiation was observed in both WK and RK. The numbers of yeast and mold were also increased in RK (p<0.05), but not in WK. There was no change observed in the scavenging activities against ABTS (2,2'-azido-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals in both kimchi broths after BLED treatment. The results of this study indicated that BLED irradiation could modulate the fermentation process and the quality characteristics of kimchi during storage.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.555-563
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• 2018

Barley has nutritional benefits due to its high dietary fiber content; therefore, the intake of whole barley grains is recommended. However, barley is often consumed in the fermented form because of the improved texture and digestibility. The present study was designed to elucidate the intracellular signaling pathway for macrophage activation by the polysaccharide BF-CP from fermented barley. BF-CP is a neutral polysaccharide, composed of neutral sugars, including glucose (70.7%), xylose (11.4%), and arabinose (9.0%). BF-CP exhibited macrophage-stimulatory activity by inducing the production of interleukin (IL)-6, tumor necrosis factor $(TNF)-{\alpha}$, and nitric oxide in RAW 264.7 macrophages. Further, BF-CP treatment strongly increased the IL-6 and $TNF-{\alpha}$ gene expression in a concentration-dependent manner. Signal transduction experiments using immunoblotting showed that BF-CP phosphorylated mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38, and nuclear factor $(NF)-{\kappa}B$, in RAW 264.7 cells in a concentration-dependent manner. These results suggest that BF-CP activates the macrophages via MAPK and $NF-{\kappa}B$ pathways, and also induces an increase in the production of cytokines.

• Food Science and Preservation
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• v.23 no.4
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• pp.538-546
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• 2016

Kochujang was prepared by replacement of rice (25%, control) with pumpkin or purple sweet potato by 0. 5, 10, and 15% (total addition ratio of rice and sweet potato=25% of sample). Effects of the addition of sweet potato on physiochemical properties of fermented Kochujang were investigated. Viable cells of yeast decreased in the sweet potato-added Kochujang at the later stage of fermentation, while there was no significant difference in the number of bacteria among the test groups. As the addition ratio sweet potato increased, ${\alpha}$-amylase activity increased while protease activity decreased. Hunter L, a, and b values of Kochujang prepared with purple sweet potato were lower than those with pumpkin sweet potato. Changes in ${\Delta}E$ value was greater in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato. Oxidation-reduction potential and water activity were higher in sweet potato-Kochujang than control, but reducing sugar content was higher in control. Alcohol and amino-type nitrogen contents were higher in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato, but it was not significant. Overall sensory acceptability was highest in Kochujang prepared with 10% of purple sweet potato while that with 15% pumpkin sweet potato was the least preferred.