• Journal of Plant Biology
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• v.7 no.3
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• pp.1-8
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• 1964

Exposing yeast cells with a certain genotype to different inducers, the ability of the yeast cells (Saccharomyces cerevisiae) to obtain enhanced fermentation for carbohydrates was observed. Regardless of the preexposure to any substrate, the inherent character incapable of fermenting a certain carbohydrate was maintained, while utilization of carbohydrates by the cells with a certain gene markers was varied by the previous conditions where they were exposed. Galactose was the best inducer for the cells to elaborate melibiase, even the galactose was not utilized as a substrate. Preexposure to galactose seemed to be necessary for the cells to utilize galactose and melibiose. Galactose fermentation by GA cells was enhanced by the exposure of the cells to galactose, but not to melibiose, raffinose, sucrose or glucose. Delayed fermentation of sucrose by the cells exposed to glucose or melibiose, but not to galactose, was observed. Raffinose fermentation was obtained by the cells with either SU RAF or GA ME genes, but the enhanced fermentation of raffinose seemed to be dependent on which inducer the cells were exposed previously and enzymes induced by the inducer to break either one of the linkages of raffinose molecule, the alpha0galactosidic or the beta-fructo-furanosidic.

• KSBB Journal
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• v.18 no.1
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• pp.14-18
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• 2003

In this study of the simultaneous saccharification and fermentation (SSF) of paper sludge, fed-batch cultivation of Lactobacillus paracasei subsp. paracasei KLB58 was attempted to produce viable KLB58 cells and lactic acid. Optimal culture conditions, including the temperature and concentration of the supplemented enzyme, were examined in terms of lactic acid production and viable cell count. When the effects of culture temperature and $\beta$-glucosidase concentration were examined in fed-batch SSF, the highest viable cell counts and lactic acid production (i.e. 5$\times$$10^9$ CFU/ml and 45 g/L, respectively) were obtained at 37$^{\circ}C$ and 2 unit/ml of $\beta$-glucosidase.

• Mycobiology
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• v.42 no.4
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• pp.361-367
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• 2014

Makgeolli, also known as Takju, is a non-filtered traditional Korean alcoholic beverage that contains various floating matter, including yeast cells, which contributes to its high physiological functionality. In the present study, we assessed the levels of ${\beta}$-glucan and glutathione in various yeast strains isolated from traditional Korean Nuruk and selected a ${\beta}$-glucan- and glutathione-rich yeast strain to add value to Makgeolli by enhancing its physiological functionality through increased levels of these compounds. Yeast ${\beta}$-glucan levels ranged from 6.26% to 32.69% (dry basis) and were strongly species-dependent. Dried Saccharomyces cerevisiae isolated from Nuruk contained $25.53{\mu}g/mg$ glutathione, $0.70{\mu}g/mg$ oxidized glutathione, and $11.69{\mu}g/g$ and $47.85{\mu}g/g$ spermidine and L-ornithine monohydrochloride, respectively. To produce functional Makgeolli, a ${\beta}$-glucan- and glutathione-rich yeast strain was selected in a screening analysis. Makgeolli fermented with the selected yeast strain contained higher ${\beta}$-glucan and glutathione levels than commercial Makgeolli. Using the selected yeast strain to produce Makgeolli with high ${\beta}$-glucan and glutathione content may enable the production of functional Makgeolli.

• KSBB Journal
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• v.21 no.4
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• pp.286-291
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• 2006

Various ${\beta}$-ionone resistant mutants were isolated from the wild-type red yeast Xanthophyllomyces dendrorhous KCTC 7704. Although the growth of X. dendrorhous KCTC 7704 was strongly inhibited at 0.025 mM ${\beta}$-ionone, one of the ${\beta}$-ionone resistant mutants isolated at 0.1 mM ${\beta}$-ionone by NTG mutagenesis showed rather 70% of relative survival at 0.15 mM ${\beta}$-ionone. Fermentation kinetics study with the mutant was carried out at $20^{\circ}C$ for 4 days in 300-mL baffled flasks. The mutant yielded up to 2.3-fold higher carotenoids content(viz. $1.2{\mu}g$ of total carotenoids per mg of dry cells) compared with the wild-type strain. The production of metabolites such as organic acids could be neglected. Studies on the kinetics with various carbon substrates revealed both an increase in final dry cell mass and a higher total carotenoids content in cell mass with glucose when compared to fructose or sucrose. As a further part of study, the effect of pH on the fermentation kinetics was investigated in glucose-limited chemostat at a dilution rate of $0.04h^{-1}$. When compared to steady-state kinetic parameters obtained at pH 4.0, a significant reduction in cell concentration at pH 3.0 and a lower carotenoids content at pH 5.2 were evident.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.70-70
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• 2019

Hepatic fibrosis is a common chronic liver diseases, characterized by the excessive deposition of extracellular matrix (ECM). Activation of hepatic stellate cells (HSC) is proliferative and fibrogenic and accumulating ECM. Transforming growth factor $(TGF)-{\beta}1$ is a critical mediator of HSC activation and ECM accumulation leading to fibrosis. Tenebrio molitor (TM), known as yellow mealworms, is reported in many countries as the nutritional value of foods. Our study has aims of finding liver function improvement effect of S. cerevisiae fermented Tenebrio molitor (SCTM) in vitro model. SCTM regulates $TGF-{\beta}1$ induced hepatic fibrosis via regulation of the $TGF-{\beta}1/Smad$ signaling. Also, we compared the components increased by yeast fermentation. It is possible to make a useful insect-derived alternative food in the improvement of hepatic liver disease.

• Molecules and Cells
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• v.28 no.4
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• pp.369-373
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• 2009

Heterologous secretory expression of endoglucanase E (Clostridium thermocellum) and ${\beta}$-glucosidase 1 (Saccharomycopsis fibuligera) was achieved in Saccharomyces cerevisiae fermentation cultures as an ${\alpha}$-mating factor signal peptide fusion, based on the native enzyme coding sequence. Ethanol production depends on simultaneous saccharification of cellulose to glucose and fermentation of glucose to ethanol by a recombinant yeast strain as a microbial biocatalyst. Recombinant yeast strain expressing endoglucanase and ${\beta}$-glucosidase was able to produce ethanol from ${\beta}$-glucan, CMC and acid swollen cellulose. This indicates that the resultant yeast strain of this study acts efficiently as a whole cell biocatalyst.

• Culinary science and hospitality research
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• v.6 no.3
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• pp.357-371
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• 2000

Changes of Microflora, enzyme activity, and contents of several taste compounds in traditional Kanjang(Korean Soy Sauce) with the variation of fermentation jars and Meju(fermented soybean brick)concentration were studied. Substitution possibilities of clay jar with glass jar and improvement possibilities of taste and nutritional value with increased Meju concentration were examined. (1) Aerobic bacteria and lactic acid bacteria were enumerated during fermentation and ripening period. But yeast and molds were hardly isolated. The number of viable cells showed small changes during fermentation and ripening period. (2) Isolated Aerobic bacteria were identified as Bacillus subtilis, Bacillus lichenformis, and lactic acid bacteria were identified as Lactlbacillus lactis lactis and lactobacillus brevis. (3) The activities of $\alpha$-amylase and $\beta$-amylase increased during fermentation period, but did not show any trend by fermentation jars or Meju concentrations. Protense activity showed small difference among four samples, and increased during the fermentation period.

• Molecules and Cells
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• v.37 no.2
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• pp.172-177
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• 2014

A glycosyltransferase, YjiC, from Bacillus licheniformis has been used for the modification of the commercially available isoflavonoids genistein, daidzein, biochanin A and formononetin. The in vitro glycosylation reaction, using UDP-${\alpha}$-D-glucose as a donor for the glucose moiety and aforementioned four acceptor molecules, showed the prominent glycosylation at 4' and 7 hydroxyl groups, but not at the $5^{th}$ hydroxyl group of the A-ring, resulting in the production of genistein 4'-O-${\beta}$-D-glucoside, genistein 7-O-${\beta}$-D-glucoside (genistin), genistein 4',7-O-${\beta}$-D-diglucoside, biochanin A-7-O-${\beta}$-D-glucoside (sissotrin), daidzein 4'-O-${\beta}$-D-glucoside, daidzein 7-O-${\beta}$-D-glucoside (daidzin), daidzein 4', 7-O-${\beta}$-D-diglucoside, and formononetin 7-O-${\beta}$-D-glucoside (ononin). The structures of all the products were elucidated using high performance liquid chromatography-photo diode array and high resolution quadrupole time-of-flight electrospray ionization mass spectrometry (HR QTOF-ESI/MS) analysis, and were compared with commercially available standard compounds. Significantly higher bioconversion rates of all four isoflavonoids was observed in both in vitro as well as in vivo bioconversion reactions. The in vivo fermentation of the isoflavonoids by applying engineered E. coli $BL21(DE3)/{\Delta}pgi{\Delta}zwf{\Delta}ushA$ overexpressing phosphoglucomutase (pgm) and glucose 1-phosphate uridyltransferase (galU), along with YjiC, found more than 60% average conversion of $200{\mu}M$ of supplemented isoflavonoids, without any additional UDP-${\alpha}$-D-glucose added in fermentation medium, which could be very beneficial to large scale industrial production of isoflavonoid glucosides.

• Journal of Microbiology
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• v.41 no.4
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• pp.284-288
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• 2003

Bacillus subtilis SFF34 degrading cholesterol was applied to reduce residual cholesterol content in fermented flatfish. When the bacterial cells were inoculated as a start culture, a maximal level (1.7 U/g) of cholesterol oxidase was obtained after 10 days, which was two times higher than that (0.8 U/g) without inoculation. Residual cholesterol contents with and without inoculation of the cells were 0.5 mg/g and 0.8 mg/g after 12 days of fermentation, respectively. Cholesterol derivatives including cholesterol- 5${\alpha},\;6{\alpha}$-epoxide, 4-cholesten-3-one and 7${\beta}$-hydroxycholesterol were detected in raw flatfish as well as fermented flatfish. Campesterol and 25-hydroxycholesterol were detected only after fermentation. However, no significant differences in their contents were observed regardless of inoculation.

• Microbiology and Biotechnology Letters
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• v.2 no.3
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• pp.127-131
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• 1974

Inhibition of over-oxidation of prednisolone in the fermentation has been studied by using vegetative cells as enzyme source. firstly, A. simplex (ATCC 6946) was demonst.ated to degrade p.ednisolone in the vegetative culture of the microorganism. Over 72％ of hydrocortisone was transformed into prednisoloneby 3 hours of the fermentation. However, the prednisolone produced was considerably oxidized forming over-oxidation product in 8hours of fermentation period with the intact cells. Secondly, in order to depress the over-oxidation and the breakdown of the steroid skeleton of prednisolone, chelating agents such as $\alpha$$\alpha$'-dipyridyl, o-phenanthroline and 8-hydroxyruinoline were added to the fermentation broth. Conseauently, the breakdown of prednisolone by the iutact cells was able to be remarkably retatded and an intermediate regarded as an oxidized product derived from prednisolone was accumulated, by the addition of $\alpha$$\alpha$'-dipytidyl in the fermentation.