Radiation Sensitivity in Relation to the Physiological State of Yeast Cells

1968 ◽  
pp. 275-282 ◽  
Author(s):  
W. Pohlit
Keyword(s):  
Physiological State ◽  
Radiation Sensitivity ◽  
Yeast Cells

scholarly journals Intracellular pH Distribution in Saccharomyces cerevisiae Cell Populations, Analyzed by Flow Cytometry

2005 ◽  
Vol 71 (3) ◽  
pp. 1515-1521 ◽  
Author(s):  
Minoska Valli ◽  
Michael Sauer ◽  
Paola Branduardi ◽  
Nicole Borth ◽  
Danilo Porro ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Flow Cytometry ◽  
Intracellular Ph ◽  
Environmental Changes ◽  
Physiological State ◽  
Yeast Cells ◽  
Cell Populations ◽  
Ph Homeostasis ◽  
Ph Distribution ◽  
External Ph

ABSTRACT Intracellular pH has an important role in the maintenance of the normal functions of yeast cells. The ability of the cell to maintain this pH homeostasis also in response to environmental changes has gained more and more interest in both basic and applied research. In this study we describe a protocol which allows the rapid determination of the intracellular pH of Saccharomyces cerevisiae cells. The method is based on flow cytometry and employs the pH-dependent fluorescent probe carboxy SNARF-4F. The protocol attempts to minimize the perturbation of the system under study, thus leading to accurate information about the physiological state of the single cell. Moreover, statistical analysis performed on major factors that may influence the final determination supported the validity of the optimized protocol. The protocol was used to investigate the effect of external pH on S. cerevisiae cells incubated in buffer. The results obtained showed that stationary cells are better able than exponentially grown cells to maintain their intracellular pH homeostasis independently of external pH changes. Furthermore, analysis of the intracellular pH distribution within the cell populations highlighted the presence of subpopulations characterized by different intracellular pH values. Notably, a different behavior was observed for exponentially grown and stationary cells in terms of the appearance and development of these subpopulations as a response to a changing external pH.

scholarly journals Effect of protease and phytase on the physiological state of alcoholic yeast in cultivation

2020 ◽  
Vol 81 (4) ◽  
pp. 98-102
Author(s):  
T. S. Kovaleva ◽  
G. V. Agafonov ◽  
A. N. Yakovlev ◽  
S. F. Yakovleva
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethyl Alcohol ◽  
Enzyme Preparation ◽  
Raw Materials ◽  
Physiological State ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Logarithmic Phase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Enzyme Preparations

Saccharomyces cerevisiae yeast is used in the production of ethyl alcohol. The main requirements for yeast used in the production of ethyl alcohol from starch-containing raw materials: alcohol yeast used in the processing of starchy raw materials must have high fermentation activity; complete fermentability of sugars, resistance to metabolic products, resistance to the development of extraneous microflora. Proteolytic enzyme preparation Prolive BS Liquid was used as a source of protease. Kingphos enzyme preparation was used as a source of phytase. The effect of the enzyme preparations of the neutral protease Prolive BS Liquid and Phytase Kingphos on the fermentation activity of alcohol yeast Saccharomyces cerevisiae race XII was studied. The maximum fermentation activity is possessed by yeast cultivated on the wort, obtained using protease and phytase. The duration of the exponential growth phase in the experiment is 14–16 hours, in the control -18–20 hours. The exponential phase is described by the Mono equation. Compared to the yeast in the control, the yeast in the experiment multiplies more intensively, and by 14–16 hours of growth, about 170 million yeast cells accumulate in the culture medium, and the yeast in the control-about 95 million yeast cells by 18–20 h of growth. The specific growth rate was maximum in the logarithmic phase and amounted to 0.35 million cells / cm3 • h in the experimental samples and 0.25 million cells / cm3 • h in the control. It was found that the maximum accumulation of yeast cells was observed when the neutral enzyme Prolive BS Liquid was added to the wort with a dosage of 0.2 units. PS/g of starch and enzyme preparation Phytase Kingfos with a dosage of 0.5 units. FS/g of starch, the yeast cell content in mature yeast reached 170 million cells / cm3 by 16-18 hours of cultivation, the yeast has a high fermentation activity.

Radiation Sensitivity of Enzymes in Wet and in Dry Yeast Cells

1957 ◽  
Vol 7 (5) ◽  
pp. 465 ◽  
Author(s):  
Franklin Hutchinson ◽  
Angela Preston ◽  
Beatrice Vogel
Keyword(s):  
Radiation Sensitivity ◽  
Yeast Cells

scholarly journals RESEARCH OF TO ULTRATHIN STRUCTURE OF CAGES OF DIFFERENT RACES OF SPIRIT YEASTS IN DEPENDENCE ON CONCENTRATION OF DRY SUBSTANCES OF WAS

2020 ◽  
Vol 14 (3) ◽  
Author(s):  
S. Kovalchuk ◽  
T. Mudrak ◽  
A. Kuts ◽  
V. Dotsenko
Keyword(s):  
Energy Saving ◽  
Dry Matter ◽  
Raw Materials ◽  
Physiological State ◽  
Yeast Cells ◽  
High Concentration ◽  
Alcohol Production ◽  
Cytological Features ◽  
The Cost ◽  
Favorable Conditions

One of the directions of introduction of resource- and energy-saving technology of alcohol brews into alcohol production is the use of highly concentrated wort from grain raw materials. The use of highly productive strains of alcoholic yeast is the basis of resource- and energy-saving technologies, a way to reduce the cost of ethyl alcohol and increase the profitability of its production. To develop the technology of highly concentrated mash from grain raw materials, it is necessary to select and select the appropriate breeds of yeast and study their morphological and physiological properties. Diagnosis of the physiological state of microorganisms. The influence of wort dry matter concentration on morphological and cytological features of the structure of yeast cells of alcoholic breeds of yeast S. cerevisiae DO–16, DO–11, K–81, XII in the conditions of cultivation on media from starch-containing raw materials was studied. The concentration of dry matter of the wort is 20 and 28%. It was found that the selected race of yeast S. cerevisiae DO–16 synthesizes the largest number of yeast cells at a concentration of 28%. Osmophilic races of S. cerevisiae DO–16 and DO–11 had smaller cell sizes and areas in comparison with thermotolerant and mesophilic races of S. cerevisiae K–81 and XII at a wort concentration of 28.0%. During fermentation, these indicators characterize the increase in the working surface of the yeast in the fermented medium, it allows to accelerate the fermentation process and ensure microbiological purity of the environment, which is especially important for highly concentrated wort. On the basis of morphological and cytological studies of the yeast race S. cerevisiae DO–16, its advantages over the races DO –11, K–81, XII for fermentation of high-concentration wort have been proved. Based on studies of the intracellular structure of the yeast S. cerevisiae DO–16, DO–11, K–81, XII, the relationship between the formation of glycogen in yeast cells and the concentration of DM wort was established. When culturing industrial yeast at a DM concentration of 28%, the glycogen content in the cells of S. cerevisiae DO–16 was significantly higher compared to the studied races, which indicates favorable conditions of the culture medium for this race.  

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

Ultrathin frozen sections of yeast without aldehyde prefixation

1978 ◽  
Vol 36 (2) ◽  
pp. 58-59
Author(s):  
K. J. Böhm ◽  
a. E. Unger
Keyword(s):  
Aqueous Solutions ◽  
Biological Material ◽  
Yeast Cells ◽  
Frozen Sections ◽  
Good Preservation ◽  
Ultrathin Frozen Sections

During the last years it was shown that also by means of cryo-ultra-microtomy a good preservation of substructural details of biological material was possible. However the specimen generally was prefixed in these cases with aldehydes.Preparing ultrathin frozen sections of chemically non-prefixed material commonly was linked up to considerable technical and manual expense and the results were not always satisfying. Furthermore, it seems to be impossible to carry out cytochemical investigations by means of treating sections of unfixed biological material with aqueous solutions.We therefore tried to overcome these difficulties by preparing yeast cells (S. cerevisiae) in the following manner:

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