• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.87-90
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• 1995

A process of organically bound germanium preparation was developed for healthy food using inorganic germanium adapted Saccharomyces cerevisiae. Adaptations of Saccharomyces cerevisiae against inorganic germanium were successively carried out through stepwise increase of GeO$_{2}$ concentration in order to produce high quantities of germanium bound yeast. Productivity of yeast and quantities of germanium in yeast were obtained 70.2 g/l and 9780 ppm, repectively, when adapted yeast and fed batch culture were used. Germanium taken-up yeast is to be organically bound germanium by evidence of no difference of germanium content after dialysis.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.365-368
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• 2006

Yeast mitochondrial transformation has been confirmed by cell death and CFP expression (CDF: cell death factor gene). Expression vector containing CDF and CFP driven by one TPI (Triose-phosphate isomerase) promoter (called artificial operon type) was bombarded to Yeast. Interestingly, yeast cells were progressively deformed into unusual shapes and lysed inner cytoplasm resulting in ell death after all after bombarding with expression vector (CDC and GFP). Since there is no report about more than one gene expression simultaneously in a single mitochondria, this report is very important to novel type of eukaryotic gene expression. Successful yeast cell transformation in this report implies possible eukaryotic mitochodrial transformation including plants and animals and moreover two or more gene expression which can be excellent applicable protocols to pharmaceutical field including antibody production.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.847-852
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• 2007

This study investigated an efficient method for the extraction of astaxanthin from the red yeast Xanthophyllomyces dendrorhous. The extraction process comprised three steps: 1) cultivating the yeast; 2) treating the yeast culture suspension with microwaves to destroy the cell walls and microbodies; and 3) drying the yeast and extracting the astaxanthin pigment using ethanol, methanol, acetone, or a mixture of the three as the extraction solvent. Ultimately, various treatment tests were performed to determine the conditions for optimal pigment extraction, and the total carotenoid and astaxanthin contents were quantified. A frequency of 2,450 MHz, an output of 500 watts, and irradiation time of 60 s were the most optimum conditions for yeast cell wall destruction. Furthermore, optimal pigment extraction occurred when using a cell density of 10g/l at $30^{\circ}C$ over 24 h, with a 10% volume of ethanol.

• IMMUNE NETWORK
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• v.6 no.2
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• pp.86-92
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• 2006

Background: Germanium compounds are increased to use in nutrient foods and medicines in terms of antibiotics to microbes, anticancer, modulation of immune system and neutralizing heavy metal toxins. Geranti Bio-Ge Yeast, containing stable organic germanium and bound to the yeast protein was developed by Geranti Pharm. LTD. and the modulation effect in the immune system was examined in vivo and in vitro. Methods: The compound, Geranti Bio-Ge Yeast, was fed to female Balb/c mice (each group has 10 mice) for 4 weeks and the yeast powder and steamed red ginseng powder were used as control during the same feeding time points. During 4 weeks there was no symptom to be considered, and after 4 weeks feeding all mice were sacrificed to check the changes of related immune cells and subsidiary responses (i.e. cell counting, FACS, MTT, LDH, PFC assay). Results: In pre-post comparison, B cell population was increased in the group of Geranti Bio-Ge Yeast in a dose dependent manner (100 to 800 mg/kg). However, the population of T cell, dendritic cell and macrophage was not comparably changed in all doses. The ability of cytokine production and proliferation was almost same level as shown in control group. In contrast, PFC assay informed that the compound increase the antibody production ability when fed over 200 mg/kg implying that the increase of PFC number might be due to the increase of B cells. Conclusion: Over the entire study, we concluded that the compound, Geranti Bio-Ge Yeast has better potential in immune response in terms of B cell proliferation than that of positive control, red ginseng, and the compound can be one of the future candidates for a new supplementary source improving immune system activity.

• KSBB Journal
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• v.6 no.3
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• pp.299-307
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• 1991

In this paper the effect of light on non-aerated Baker's Yeast(Saccharomyces cereuisiae) production and the protein excretion to the extracellular fluid is studied. Previous results in our laboratory indicate that at pH=5 and T-32$^{\circ}C$ yeast may be affected by light, but those differences seem to be within statistical variation of the data. In this paper, cell and extracellular protein concentrations along with redox potential are monitored for batch fermentations in the presence and absence of light at pH levels of 3 and 5 and at 31$^{\circ}C$, in order to explore whether possible light effects can be more readily discerned at lower pH values. Yeast particle size distributions are also determined over the course of fermentation using a particle counter in order to add one more measuring tool to our usual cell and total protein measurements. An apparently noticeable difference in the redox potential is observed between the light and the dark runs for early times for the pH=3 runs. The particle size distributions show differences in the particle diameters between light and dark runs at pH=3, but those differences fall within one standard deviation of the mean particle diameters.

• Journal of Ginseng Research
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• v.3 no.2
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• pp.95-104
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• 1979

The effects of ginseng extracts on carbon dioxide generation, alcohol fermentation, and yeast cell production by Saccharomyces cerevisiae were investigated. The results are as follows. 1) In the process of fermentation, CO2 generation by yeast is faster in ginseng extracts media of 0.3%, 0. l% than in control. As the concentration of the extracts increases by 0.7% and 1.5%, CO2 generation is decreased. Among all these concentrations, CO2 generation is fastest in 0.3% of the extracts. 2) In the process of fermentation, the production of alcohol is larger in the order of 0.3%, 0.7% and 0.1% than in the control and least in 1.5%. 3) The number of yeast cell rapidly increased from 12 hours to 18 hours after cultivation and conspicuously increased in the order of 0.3%, 0.7%, 0.1%, control and 1.5%. 4) Dried yeast cell weight increased more in all the above concentration than control and among these it increased visibly in 0.3% of the extracts.

• Molecular & Cellular Toxicology
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• v.3 no.1
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• pp.19-22
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• 2007

Optic tweezer is powerful tool to investigate biologic cells. Of eukaryotic cells, it was poorly documented regarding to optic trapping to manipulate yeasts. In preliminary experiment to explore yeast biology, interferometric optical tweezers was exploited to trap and manipulate budding yeasts. Successfully, several budding yeasts are trapped simultaneously. We found that the budding direction of the daughter cell was almost outward and the daughter cell surrounded by other yeasts grows slowly or fail to grow. Thus it was assumed that neighboring cells around budding yeast may be critical in budding and the growth of daughter cells. This is first report pertaining to the pattern of yeast budding under the optical trap when multiple yeasts were trapped.

• Journal of Life Science
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• v.8 no.2
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• pp.197-202
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• 1998

The cell of Kluyveromyces fragilis yeast, which is worthy of an algal substitute, was disrupted by a chemical treatment to increase the digestion of filter-feeders that yeasts are fed to. The optimum conditions of the chemical treatment were obtained by incubating yeasts at 3$0^{\circ}C$ for one hour after treated by 1 M of Na$_{2}$-EDTA that was dissolved in 0.2 M of Tris-buffer and by 0.3 m of 2-mercaptoethanol. The percentage of protop[last production was about 30%. The percentage could be doubled by the pretreatment of three times of 30 seconds sonication.

• KSBB Journal
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• v.6 no.2
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• pp.189-194
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• 1991

The effect of wtlitc light on unaeraten growth of Baker's yeast and the accompanying ethanol production has been studied in a batch process at 27$^{\circ}C$. Over the 80-hour period of the Champagne yeast process without pH control, the cull growth was inhibited by the fluorescent light. Another observed difference between the runs is that the drop and subsequent rise in redox potential occurred much sooner in the fermentation with light than in the fermentation without light. This preliminary study indicated that ethanol production could be enhanced by light as the cell concentration is repressed. The possible pathway, shift of the sugar substrate toward ethanol and away from cells was manifested by another difference as well. As observed under the microscope, many of the yeast cells grown under light budded without dividing by the normal fission process as they did in the dark. Furthermore, the undivided and branched (light grown) cell did not agglutinate at the end of the fermentation process as did the distinct spherical (dark grown) cells.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.1-10
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• 1986

To evaluate the possible utilization of ginseng by-products, chemical components of ginseng residue, reducing ability of DPPH, effect of residue extract on the yeast growth, amino acid contents of yeast cell, increase of residue extract yield by enzyme treatment were studied. Alcohol and water extract residue contained 43-46% total reducing sugar and 14-15% crude protein, while alcohol extract residue had 0.18% n-BuOH extract. Water extract of alcohol extract residue had about 45% reducing ability of DPPH in comparison with that of alcohol extract from ginseng roots. Essential nutrients for the yeast growth were found in extract when Saccharomyces cerevisiae was cultured in Czapeck medium, a compound medium, with the residue. The addition of residue extract to malt medium, a natural medium, enhanced 30-40% yeast growth. And content of each amino acid in yeast cell cultured on malt medium with ginseng residue extract was much more than that of the cell cultured without ginseng extract, but amino acid composition of yeast cell did not differ from one another. The treatment of alcohol extract residue with cellulase increased 250% yield of residue extract.