• Journal of Microbiology
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• v.35 no.3
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• pp.228-233
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• 1997

The MTF1 gene of Saccharomyces cerevisiae encodes a 43 kDa MITOCHONDRIAL RNA polymerase specificity factor which recognizes mitochondrial promoters to initiate correct transcription. To better understand structure-function of the MTF1 gene as well as the transcription mechanism of mitochondrial RNA polymerase, two cold-sensitive alleles of the MTF1 mutation were isolated by plasmid shuffling method after PCR-based random mutagenesis of the MTF1 gene. The mutation sites were analyzed by nucleotide sequencing. These cs phenotype mtf1 mutants were respiration competent on the nonfermentible glycerol medium at the permissive temperature, but incompetent at 13.deg.C. The cs phenotype allele of the MTF1, yJH147, encoded an L146P replacement. The other cs allele, yJH148, contained K179E and K214M double replacements. Mutations in both alleles were in a region of Mtflp which is located between domains with amino acid sequence similarities to conserved regions 2 and 3 of bacterial s factors.

• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.299-306
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• 1999

For the synthesis of new antifungal agents, We have synthesized four new ketoconazole derivatives were synthesized by the reaction of cis-[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)-1,3-dioxolan-4-yl]methane sulfonate with isolated fig compounds. These compounds were showed strong antifungal activity against C, albicans ATCC 10231. C, utilis. S, cerevisiae ATCC 9763. A and niger ATCC 9029. Among them, sample No.(13) showed potent inhibition activity. Generally, other samples showed biological activity in vitro test. The above results showed the possibility of the development of new antifungal agents.

• Food Science and Preservation
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• v.18 no.4
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• pp.559-566
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• 2011

In this study, the good brewing conditions for the 24 $^{\circ}Brix$ freeze-concentrated apple wine were investigated. The four selected Saccharomyces cerevisiae strains MM10, SS89, SS812, and WW108, could ferment quickly when brewed with high sugar levels. During the fermentation, the reducing sugar contents slowly declined while the total acid in all the yeasts increased and the final alcohol content was 12-13%, a typical wine's alcohol content. The viable counts were shown to be 6-6.8 log cfu/ml. During the fermentation, the organic acid content was shown to be within the range of 2.36-3.11%, and the free sugar content, except for the SS89 and WW108 strains, was shown to consist only of sorbitol, although fructose was somewhat detected in the SS89 and WW108 strains. Methanol was not detected, or only a trace of it was detected, and the aldehyde content was 107.68-114.27 ppm. As for the fusel oil contents, a trace of propanol was detected. Isobutanol and butanol were present in 40.16-54.65 and 25.47-27.73 ppm, respectively. The isoamy1 alcohol content was shown to be the highest (108.88-217.26 ppm). The final total phenolic compounds were shown to be 0.1-0.16%. The final Hue values were shown to be 1.3-3.6, and the final intensity was 0.1-0.45. The lightness (L) was within the range of 91.78-98.51, the redness (a) was at a neutral position at red and green, and the yellowness (b) was within the range of 2.38-7.7. In the sensory evaluation, the SS812 strain was found to be the best in terms of color, the SS89 strain in terms of odor, and the WW108 strain in terms of taste. Overall, SS812 was found to be the best apple wine.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.236-245
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• 1999

Andong Soju is a Korean traditional distilled liquor brewed with Nuruk which is cultured with wild microorganisms. To provide useful information for scientific production and systematic quality control of traditional distilled liquor, the effects of mixed culture of the alcoholic yeasts and saccharifying molds isolated from the Nuruk, and mashes on the flavor and sensory characteristics were investigated. Distillate from mashes cocultured with Saccharomyces cerevisiae and Hansenula anomala using Mucor Nuruk was compared with distillate from mashes brewed with Andong Nuruk and with distillate from plant fermented mashes to analyze their flavor characteristics. The volatile flavor compounds in distillates were analyzed by GC and GC-MS using direct injection, solvent extraction, and purge & trap methods. Alcohols such as 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, and 2-phenyl ethanol; aldehydes such as acetaldehyde and 2-furancar-boxaldehyde; esters such as ethyl ester of acetic acid, hexanoic acid, octanoic acid, decanoic acid; alkanes, alkenes, ketone, sulfur, and pyrone compounds were detected. Alcohols were chief components of flavor compounds. No significant difference in overall acceptability test was shown among three experimental groups(p<0.05), but Nuruk-like aroma, Kaoliangchiew-like aroma, sweet taste, and well rounded mouthfeel showed significant differences among them(p<0.05).

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.390-397
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• 1991

Ethanol production by calcium alginate-immobilized baker's yeast (Saccharor/tyces cereviszae) was studied in the batch fermentation using glucose medium as a feed. Immobilied cells were stable between $30^{\circ}C$ and $40^{\circ}C$ whereas free cells were stable between $30^{\circ}C$ and $37^{\circ}C$ The beads were showed constant ethanol productivity during 720 hours (30 days) over. Fermentation characteristics of immobilized baker's yeast were examined changing the initial glucose concentration of broth in fermentation. Initial glucose concentrations employed were 50, 100, 150 and 200 g/l, respectively. In 15% gucose medium, maximum specific growth rate, maximum ethanol yield and ethanol concentration were observed as 0.092 $h^{-1}$, 0.45, 67.5 g/l, respectively.

• BMB Reports
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• v.33 no.3
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• pp.263-267
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• 2000

We cloned $hda1^+$ (histone deacetylase 1) of fission yeast Schizosaccharomyces pombe. The hda1 of S. pombe was previously reported to encode for an active histone deacetylase (Rundlett et al., 1996; Olsson et al., 1998). The $hda1^+$ is phylogenetically related to the new open reading frame HOS2 of Saccharomyces cerevisiae and only shows a partial homology to the well-known histone deacetylase subclasses, RPD3 and HDA1. A single hda1 mRNA of 1.8 kb was detected at the same level in actively growing and nitrogen-starved cells. When highly over-expressed in S. pombe from an inducible promoter, $hda1^+$ inhibited cell proliferation and caused defects in morphology and cell division. The increased histone deacetylase activity was detected in hdar over-expressing cells. These results suggest that the Hda1p should function on the regulation of cell division possibly by (Allfrey, 1966) direct deacetylation of cytoskeletal (Wade et al., 1997) and cell division regulatory proteins, (Wolffe, 1997) or by controlling their gene expressions.

• Journal of Microbiology
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• v.45 no.1
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• pp.53-57
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• 2007

A number of essential oils from Mongolian aromatic plants are claimed to have antimicrobial activities. The essential oil of Dracocephalum foetidum, a popular essential oil used in Mongolian traditional medicine, was examined for its antimicrobial activity. Eight human pathogenic microorganisms including B. subtilis, S. aureus, M. lutens, E. hirae, S. mutans, E. coli, C. albicans, and S. cerevisiae were examined. The essential oil of Dracocephalum foetidum exhibited strong antimicrobial activity against most of the pathogenic bacteria and yeast strains that were tested; by both the agar diffusion method and the minimum inhibitory concentration (MIC) assay ($MIC\;range\;was\;26-2592{\mu}g/ml$). Interestingly, Dracocephalum foetidum even showed antimicrobial activity against methicilin-resistant Staphylococcus aureus (MRSA) strains. We also analyzed the chemical composition of the oil by GC-MS and identified several major components, including n-Mentha-1,8-dien-10-al, limonene, geranial, and neral.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.77-81
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• 2006

The dextransucrase activity of microorganisms which were identified as contributing to the fermentation of jeungpyeon made with yeast was measured. The dextran generated during fermentation was quantified and the viscosity changes were measured. The mechanism of network structure formation was clarified by observing the inside of the network structure over the fermentation periods ranging from 1 to 7 hr using scanning electron microscopy (SEM). The pH of jeungpyeon batter decreased significantly as the fermentation proceeded, whereas the viscosity increased. The identified lactic acid bacteria (LAB) were Leuconostoc mesenteroides subsp. mesenteroides, Pediococcus pentosaceus, Tetragenococcus halophilus, and Leuconostoc mesenteroides subsp. dextranicum. The yeast was identified as Saccharomyces cerevisiae A/Tor. Pretorien. The dextransucrase extracted from those microorganisms showed high activity. On the other hand, the amount of dextran generated from the batter increased significantly beyond 2 hr of fermentation, and the viscosity increment showed a similar trend. The SEM photos showed that the most homogeneous fine network structure was observed in the batter fermented for 2 hr. Therefore, we assumed that the dextran that was generated by microorganisms during fermentation interacted with the components of the batter to increase the stability of the network structure.

• Journal of Life Science
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• v.23 no.6
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• pp.796-803
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• 2013

Property changes and bacterial characterizations by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were investigated during the fermentation of Makgeollies by 5 isolated yeast strains. Changes of pH were large between day 0 (pH 6) and day 2 (pH 3) and showed less variation after then. ANOVA analyses revealed that pHs were statistically different with fermentation times (p<0.001), while strains (p=0.60) did not. Acidities were changed from 0.19 to 1.04% and showed rather high increase from day 2, and fermentation times (p<0.001) and strains (p=0.006) represented statistical differences. All strains showed less than 0.150% at amino-type nitrogen contents except S strain showed 0.442% at day 8, and there were no statistical differences with fermentation times (p=0.4558) and strains (p=0.3513). Saccharinities of C strain were higher from day 4, and fermentation times (p<0.0001) and strains (p=0.007) showed statistical differences. Large variation of alcohol concentrations (%) were observed between day 0 (0%) and day 2 (10%) and showed less variation after day 2, and there was no statistical difference with strains. Dominant prokaryotes were Lactobacillus fermentum and Pediococcus pentosaceus, which producing acids and functional materials. Dominant eukaryote was Saccharomyces cerevisiae, which might be resulted from addition of yeasts.

• Journal of Animal Science and Technology
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• v.55 no.1
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• pp.41-49
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• 2013

In vitro and in situ incubation studies were conducted to determine effects of yeast culture supplements (Saccharomyces cerevisiae) on cellulolytic bacterial function and fiber digestion in rice straw. In vitro dry matter digestibility of rice straw gradually increased according to supplemental levels of yeast culture (0.0, 0.2, 0.4, 0.6, 0.8 and 1.0%). Digestibility of rice straw started to increase apparently when yeast culture was added more than 0.6% level (p<0.05). Also, we reconfirmed that in vitro dry matter digestibility was significantly increased by 0.6% of yeast culture addition in 4% NaOH treated and non-treated rice straws (p<0.05). When in situ dry matter digestibility was tested in Korean native goats fed basal diet or experimental diet which contained 1.0% of yeast culture, the yeast culture feeding improved in situ dry matter digestibility in both 4% NaOH treated and non-treated rice straws (p<0.05). In case of real-time PCR monitoring cellulolytic bacterial function, the bacterial population attached on rice straw showed the increasing trends with higher level of yeast culture spraying on rice straw. F. succinogenes and R. flavefaciens were significantly increased in accordance to spraying levels of yeast culture (0.0, 0.1 and 0.3%) at both 12 and 24 hrs of in situ incubation (p<0.05). R. albus was significantly higher population in yeast culture spraying than non-soraying at 12 hrs of in situ incubation (p<0.05). These bacterial populations were showed the increasing trends with digestibility enhancement of rice straw according to the higher levels of yeast culture supplement. Overall, these results clearly suggest that the presence of yeast culture result in noticeable increase of rice straw digestion, which is modulated via good effect on cellulolytic bacterial attachment to fiber substrates.