• Animal cells and systems
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• v.6 no.4
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• pp.335-339
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• 2002

Mouse T cells overexpressing the SRG3 protein displayed morphological changes; the cells were enlarged and their shapes were irregular compared to the normal parental cells. In addition, growth rate of the cells was dramatically reduced and their DNA contents were increased. The increased DNA contents were due to an increase in number of chromosomes in these cells. We have observed similar results in S. cerevisiae cells overex-pressing the yeast SWI3 protein. Yeast cells overexpressing SWI3 protein These results suggest that the SRG3/SWI3 protein plays an important role in cell growth and cell cycle progression.

• Journal of Microbiology
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• v.34 no.4
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• pp.327-333
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• 1996

Yeast, like many other microbes, encounters large variations in ambient pH in their natural environments. Microorganisms capable of growing over a wide pH range require a versatile, efficient pH homeostatic mechanism protecting intracellular processes against extremes of pH. In several organisms, fusions to the bacterial lacZ gene have been extremely useful for the identification of genes expressed at different time during the life cycle or under different growth conditions. In this study, using the lacZ gene screening system, we surveyed a large number of yeast strains with lacZ insertion to identify genes regulated by pH. A yeast genomic library was constructed and inserted with lacZ by a shuttle mutagenesis procedure. The yeast transformants were individually picked up with a toothpick, replica-plated, and grown in alkaline pH medium. Among the 35,000 colonies screened, 10 candidate strains were identified initially by the $\beta$-gal assay. We finally confirmed two yeast strains carrying the genes whose expression are strictly dependent on pH of growth medium. One of the fusions showing a 10-fold induction in expression level in response to alkali pH was selected and further characterized. The pH-regulated gene was cloned by inverse PCR and a partial sequence of the gene was determined. Identification and characterization of the gene is currently under investigation.

• Animal Bioscience
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• v.35 no.9
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• pp.1400-1407
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• 2022

Objective: This research determined the chemical composition and the apparent and standardized ileal digestibility (AID and SID) of crude protein (CP) and amino acids (AA) in whole yeast and autolyzed yeast derived from sugarcane ethanol production fed to growing pigs. Methods: Six growing pigs were randomly allocated in a replicated 3×3 Latin square design with 3 diets and 3 periods of 7 days each, resulting in a total of 6 experimental replications. Three assay diets were formulated using whole yeast, autolyzed yeast, or soybean meal as the sole sources of dietary CP and AA. Pigs were allowed to adapt to the assay diets for 5 days. Thereafter, ileal digesta samples were collected continuously for 8 hours on days 6 and 7. Results: There was no difference in the chemical composition between whole yeast and autolyzed yeast, but whole yeast had low digestibility of CP and AA due to the presence of a rigid cell wall. As conducting autolysis can induce cell wall damage, the AID and SID of CP and AA were greater in autolyzed yeast than in whole yeast. Conclusion: The information obtained on the SID of CP and AA in both yeast products can be used for the accurate estimation of the bioavailability of CP and AA in feed formulations. The yeast products derived from sugarcane ethanol production are an alternative protein source in pig diets.

• Journal of Nutrition and Health
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• v.10 no.1
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• pp.10-17
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• 1977

This study was designed to compare the Biological effects of the cereals and legumes Proteins on albino rats. Fifty weaning albino rats weighing $49\;gr{\pm}2$ in both sexes were divided into 5 groups and fed corn crude protein diet, wheat crude protein diet, soybean protein diet, yeast diet and 30% sugar-casein diet for the control group. The protein contains same levels with isocaloric values each diet. After 12 weeks the rats were sacrificed for chemical analysis and the results are as follow ; 1. The highest food consumption was found in the groups of yeast and soybean, and the lowest was found in the groups of wheat diet and corn diet. 2. The groups of yeast & soybean protein showed the highest body weight increase, while the groups of wheat diet and corn diet showed the lowest. 3. Highly significant difference was found between the standard group and the groups of corn protein and soybean protein in Food Efficiency Ratio. (F. E. R.) (p<0.01). 4. Protein Efficiency Ratio showed a similar pattern as the F.E.R., however, there was no significant differences among the groups. 5. The kind of diets did not influence the hematology of the subjects. 6. The rate of nitrogen retention of male standard group was lower compared with all the experimental groups (p<0.01), and that of female soybean group was higher than any other groups (p<0.01). 7. Female corn diet group had the lowest organ weights, as found in the growth rate, which was significant (p<0.01). In the male corn diet group only the kidney showed significantly low in weight (p<0.01), and the spleen of male yeast group was also shown low with significance (p<0.01). 8. Nitrogen retentions of the liver and muscle in male corn diet group were lower than any other groups (p<0.05), and the brain nitrogen content of female standard group was high with significance (p<0.01). According to the results above, yeast and soybean protein can be regarded as a nutritious and also inexpensive protein sources.

• Korean Journal of Microbiology
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• v.26 no.1
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• pp.67-71
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• 1988

It has been observed that white loght can suppress both cell growth and protein secretion in Baker's yeast. This effect was explored in batch liquid fermentations. Possible applications of this phenomenon are (a) use as a tool for pre-concentrating excreted enzymes prior to subsequent purification and (b) an engineering variable for regulation yeast fermentations.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.286-291
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• 2002

Histone deacetylase I (HDAC1) works as one of the components in a nucleosome remodeling (NuRD) complex that consists of several proteins, including metastasis-associated protein 1 (MTA1). Since the protein-protein interaction of HDAC1 and MTA1 would appear to be important for both the integrity and functionality of the HDAC1 complex, the interruption of the HDAC1 and MTA1 interaction may be an efficient way to regulate the biological function of the HDAC1 complex. Based on this idea, a yeast two-hybrid system was constructed with HDAC1 and MTA1 expressing vectors in the DNA binding and activation domains, respectively. To verify the efficiency of the assay system, 3,500 microbial metabolite libraries were tested using the paper disc method, and KB0699 was found to inhibit the HDAC1 and MTA1 interaction without any toxicity to the wild-type yeast. Furthermore, KB0699 blocked the interaction of HDAC1 and MTA1 in an in vitro GST pull down assay and induced morphological changes in B16/BL6 melanoma cells, indicating the interruption of the HDAC1 complex function. Accordingly, these results demonstrated that the yeast assay strain developed in this study could be a valuable tool for the isolation of a HDAC1 complex disruptor.

• The Journal of Natural Sciences
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• v.4
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• pp.1-10
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• 1991

The expression of the cloned Saccharomyces cerevisiae antioxidant protein gene in E. coil on plasmid was studied. Introduction of the DNA encoding yeast thiol-specific antioxidant protein into expression vector, PKK 223-3, having the tac promoter resulted in the production in E. coil of a Mr 27,000 polypeptide. This protein represented as much as about 1% of the bacterial soluble protein and showed the thiol-specific antioxidant properties. The bacterial protein showed physico-chemical properties indistringuishable from those of the yeast protein.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.108-112
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• 1992

To investigate the expression and the secretion of heterologous proteins in yeast, we constructed an yeast secretion vector and produced a human secretory protein, .alpha.-1-antitrypsin (.alpha.-1-AT), from yeast cells. The secretion vector pGAT8 was constructed by inserting the signal sequence of yeast acid phosphatase gene (PH05) into the .alpha.1-AT expression vector pGAT6 which contained .alpha.-1-AT cDNA fused to GAL10-CYC1 promotor. The .alpha.-1-AT was produced efficiently in the yeast cells transformed with plasmid pGAT8, which was onfirmed both by the .alpha.-1-AT activity assay and by the immunoblot method using .alpha.-1-AT antibody. We also showed the secretion of .alpha.-1-AT into the culture media and into the periplasmic space by immunoblot.

• Korean Journal of Poultry Science
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• v.24 no.2
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• pp.67-72
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• 1997

In order to investigate the effect of feeding live yeast (Sacckaromyces cerevisiae) on the growth performance and changes of intestinal microorganism (E. coli), a growth assay was conducted with 144 broiler chicks. Treatments were consisted of corn-soybean meal control, 0.05% live yeast, and 0.05% dead yeast. Most of the chick protein of the live yeast was in the pure protein form, and had a high amino acid composition with 47% of essential amino acids and 53% of non-essential amino acids. No differences in growth performance were shown among dietany treatments. Total number of E. coli in the small intestine of chicks fed either live or dead yeast was significantly reduced compared to chicks fed the control diet. Although the changes of E. coli in the cecum were not identical to differences in the small intestine, the changes of E. coli in the cecurn had a similar trend.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.263-269
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• 1992

Radish green juice was used as a dual source for the production of plant protein precipitate and Candida utilis biomass. Precipitates ranging from 10.0 to 16.5g were obtained from a liter of radish green juice by heating at 80-10$0^{\circ}C$C for 1 to 10 min or by modification of the pH of radish green juice. Crude protein content of the precipitate was between 25 and 38%. The residue remaining after protein precipitation was used in turn for the cultivation of the yeast, C. utilis, in order to produce yeast biomass. C. utilis grew well in radish green residual juice and completed growth within 24 hr at 3$0^{\circ}C$ and 200rpm in shake flask experiments. Maximum dry cell weight obtainable from a liter of radish green residual juice was 19.5g, when the yeast was grown on the juice residue diluted 3 times or more with water to make sugar content be equal to or less than about 1.0%. Supplementation of 3-fold diluted radish green residual juice with yeast extract and (NH$_4$)SO$_4$ enhanced yeast biomass production and cell protein content significantly. Total high protein material obtainable from a liter of radish green juice was 33.0g.