scholarly journals A KINETIC ANALYSIS OF THE ENDOGENOUS RESPIRATION OF BAKERS' YEAST

1936 ◽  
Vol 19 (3) ◽  
pp. 461-477 ◽  
Author(s):  
T. J. B. Stier ◽  
J. N. Stannard
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nutrient Medium ◽  
Co2 Production ◽  
Endogenous Respiration ◽  
Second Phase ◽  
O2 Consumption ◽  
Yeast Saccharomyces Cerevisiae ◽  
First Order ◽  
Constant Rate ◽  
Two Phases

The process of endogenous respiration of two strains of bakers' yeast, Saccharomyces cerevisiae, was examined kinetically. The rate of respiration with respect to time in a non-nutrient medium was found to exhibit two phases: (a) a period of constant rate of O2 consumption and CO2 production (R.Q. = 1) characteristic of cells with ample concentrations of stored material; (b) a first order decline in rate of respiration with respect to time, where the rate was proportional to the concentration of some substrate, S. (R.Q. = 1 throughout second phase.) The nature of this substrate was reexamined and the evidence summarized confirms the notion that it is a carbohydrate, probably glycogen. These phases of endogenous respiration were shown to depend upon the age of the culture and the amount of substrate available.

scholarly journals Ascospore Formation in the Yeast Saccharomyces cerevisiae

2005 ◽  
Vol 69 (4) ◽  
pp. 565-584 ◽  
Author(s):  
Aaron M. Neiman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membranes ◽  
Secretory Pathway ◽  
Diploid Cell ◽  
Spore Wall ◽  
Second Phase ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Membrane Compartments ◽  
Two Phases

SUMMARY Sporulation of the baker's yeast Saccharomyces cerevisiae is a response to nutrient depletion that allows a single diploid cell to give rise to four stress-resistant haploid spores. The formation of these spores requires a coordinated reorganization of cellular architecture. The construction of the spores can be broadly divided into two phases. The first is the generation of new membrane compartments within the cell cytoplasm that ultimately give rise to the spore plasma membranes. Proper assembly and growth of these membranes require modification of aspects of the constitutive secretory pathway and cytoskeleton by sporulation-specific functions. In the second phase, each immature spore becomes surrounded by a multilaminar spore wall that provides resistance to environmental stresses. This review focuses on our current understanding of the cellular rearrangements and the genes required in each of these phases to give rise to a wild-type spore.

scholarly journals Influence of the parameters processes of cultivation of yeast Saccharomyces cerevisiae in simple periodic culture on the yield and biosynthesis of some cellular components

2018 ◽  
Vol 80 (2) ◽  
pp. 175-181 ◽  
Author(s):  
T. V. Meledina ◽  
V. A. Ivanova ◽  
H. Razan ◽  
O. V. Golovinskaya ◽  
I. V. Novikova ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Nutrient Medium ◽  
Initial Density ◽  
Nutrient Deficiencies ◽  
Nutrient Media ◽  
Yeast Saccharomyces Cerevisiae ◽  
Individual Factor ◽  
Cellular Components ◽  
The Impact

The growth and multiplication of the industrially significant yeast Saccharomyces cerevisiae is primarily determined by the balance of the composition of the nutrient medium used. In order to prevent a decrease in the speed of the biotechnology process and to achieve the optimal yield of the desired biosynthesis product (biomass), it is necessary to introduce such nutrient deficiencies as vitamins and trace elements into the nutrient medium. At present, there is much information about the influence of different environmental factors on the growth and multiplication of microorganisms. However, the potential possibilities of microbial cultures have not been fully used. Researchers during the preparation of nutrient media until recent time mainly use the methods of establishing one-factor dependence that are based on the principle of alternating change of each nutrient media factor with the others being constant. In this work, the impact on the biomass yield of various process parameters in their interactions is investigated. A multifactor dependence is established using the methods of mathematical design of an experiment. These methods allow both to study the effects of a large number of factors and to construct a mathematical model of the process revealing the quantitative value of each individual factor and to take into account the interfactor interactions in the system .The cultivation of the yeast Saccharomyces cerevisiae was conducted in a simple periodic culture. The factors used were: the amount of inoculum, the content of nitrogen, phosphorus and biotin in the medium. Using experimental data and multifactor analysis, it was found that under these conditions, the content of biotin in the medium mostly affects the biomass synthesis. It was established that, in an optimally composed media, the economic coefficient was independent of the size of the seeding. Moreover, it was shown that the size of the fund of free amino acids is inversely related to the consumption of the seeding: with an increase in the initial density of the population, the number of amino acids in cells decreases.

scholarly journals INHIBITION OF GROWTH BY AMBER SUPPRESSORS IN YEAST

Genetics ◽  
1976 ◽  
Vol 82 (2) ◽  
pp. 233-249
Author(s):  
Susan W Liebman ◽  
Fred Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Growth Rates ◽  
Nutrient Medium ◽  
Normal Growth ◽  
Yeast Saccharomyces Cerevisiae ◽  
Highly Efficient ◽  
Critical Range ◽  
Inhibition Of Growth ◽  
Amber Suppressor

ABSTRACT Strains of the yeast Saccharomyces cerevisiae that contain highly efficient amber (UAG) suppressors grow poorly on nutrient medium, while normal or nearly normal growth rates are observed when these strains lose the suppressors or when the suppressors are mutated to lower efficiencies. The different growth rates account for the accumulation of mutants with lowered efficiencies in cultures of strains with highly efficient amber suppressors. Genetic analyses indicate that one of the mutations with a lowered efficiency of suppression is caused by an intragenic mutation of the amber suppressor. The inhibition of growth caused by excessive suppression is expected to be exacerbated when appropriate suppressors are combined together in haploid cells if two suppressors act with a greater efficiency than a single suppressor. Such retardation of growth is observed with combinations of two UAA (ochre) suppressors (Gilmore 1967) and with combinations of two UAG suppressors when the efficiencies of each of the suppressors are within a critical range. In contrast, combinations of a UAA suppressor and a UAG suppressor do not affect growth rate. Apparently while either excessive UAA or excessive UAG suppression is deleterious to yeast, a moderate level of simultaneous UAA and UAG suppression is not.

scholarly journals Study of the Effect of Squalene Epoxidase Activity on Squalene Biosynthesis by Yeast Saccharomyces Cerevisiae VGSh-2

2022 ◽  
Author(s):  
Olga L. Meshcheryakova ◽  
Galina P. Shuvaeva ◽  
Tatyana V. Sviridova ◽  
Anna A. Tolkacheva ◽  
Olga S. Korneeva
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Industrial Production ◽  
Nutrient Medium ◽  
Squalene Epoxidase ◽  
Specific Inhibition ◽  
Microbial Synthesis ◽  
Yeast Saccharomyces Cerevisiae ◽  
Aerobic Conditions ◽  
Key Enzyme ◽  
Antimycotic Drug

The researchers of this study investigated the biosynthesis of squalene by the yeast S. cerevisiae VGSH-2 through the activity of squalene epoxidase, which is a key enzyme in the conversion of squalene to ergosterol. It has been established that under aerobic conditions the antimycotic drug terbinafine promotes the switching of ergosterol formation to squalene synthesis. This switch occurs through specific inhibition of the squalene epoxidase of the yeast S. cerevisiae VGSH-2, thus increasing the biosynthetic ability of the yeast towards squalene. According to the results of this study, the optimal concentration of terbinofine in the nutrient medium was 0.3 μmol / cm3 . This concentration led to a 5-fold decrease in squalene epoxidase activity and a 7-8 times increase in squalene synthesis. The results obtained can be used to develop a competitive technology for the industrial production of squalene by microbial synthesis. Keywords: squalene, yeast, biosynthesis, inhibition of activity, terbinafine, squalene epoxidase, Saccharomices cerevisiae VGSH-2

The Sparing Effect of UV- and X-ray-dose-fractionation in Starved Diploid Yeast

1971 ◽  
Vol 26 (2) ◽  
pp. 129-133 ◽  
Author(s):  
Jürgen Kiefer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nutrient Medium ◽  
Complete Recovery ◽  
Dose Fractionation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Partial Synchronization ◽  
X Ray ◽  
Cell Progression ◽  
Sparing Effect

The sparing effect of UV- and X-ray dose fractionation and the influence of pre-exposure starvation were investigated in diploid yeast, Saccharomyces cerevisiae. A sparing effect could be demonstrated in starved cells if they were incubated in fresh nutrient medium during the fractionation interval. The time necessary for complete recovery, however, was greatly increased as compared to unstarved stationary phase cells. The possible role of cell progression and partial synchronization is discussed.

scholarly journals THE METABOLIC SYSTEMS INVOLVED IN DISSIMILATION OF CARBOHYDRATE RESERVES IN BAKERS' YEAST

1936 ◽  
Vol 19 (3) ◽  
pp. 479-494 ◽  
Author(s):  
T. J. B. Stier ◽  
J. N. Stannard
Keyword(s):  
Normal Structure ◽  
Hydraulic Press ◽  
Co2 Production ◽  
Endogenous Respiration ◽  
Yeast Saccharomyces Cerevisiae ◽  
Alcohol Production ◽  
Carbohydrate Reserves ◽  
Low Concentrations ◽  
Metabolic Systems ◽  
Protoplasmic Structure

Evidence is presented showing that the dissimilation of carbohydrate reserves in two strains of bakers' yeast, Saccharomyces cerevisiae, is a purely respiratory process. Endogenous respiration is KCN-labile. Our own experiments together with various accounts and data given in the literature show that the same "oxygen-transporting mechanism" functions in both endogenous and exogenous metabolism. However, the lack of sensitivity of the endogenous system of reactions to low concentrations of monoiodoacetic acid, the absence of anaerobic CO2 production, and the absence of alcohol production, demonstrate that fermentation is not involved in the dissimilation of the carbohydrate reserves. Throughout the experiments the endogenous respiration behaved functionally as a unitary system of reactions. The O2 consumption and CO2 production were parallel at all times; i.e., the R. Q. was consistently 1. Monoiodoacetic acid and KCN in concentrations from 10–5 to 10–1 molar affected both O2 uptake and CO2 production to the same extent. The only agents known to alter the value of the R. Q. were those which disrupted the normal protoplasmic structure, viz. grinding the cells with sand, plasmolyzing them with toluol and hypertonic salt solutions, or pressing them in a hydraulic press. These agents brought about a vigorous anaerobic CO2 production accompanied by an accumulation of alcohol in the medium. The unitary character of endogenous respiration is exhibited only when the normal structure of the cell is kept intact; apparently it depends upon the maintenance of a chambered (or compartmental) architecture of the cell.

scholarly journals Treatment of Rhenium-Containing Effluents Using Environmentally Friendly Sorbent, Saccharomyces cerevisiae Biomass

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4763
Author(s):  
Inga Zinicovscaia ◽  
Nikita Yushin ◽  
Dmitrii Grozdov ◽  
Konstantin Vergel ◽  
Pavel Nekhoroshkov ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metal Removal ◽  
Copper Ions ◽  
Isotherm Models ◽  
Solution Ph ◽  
Yeast Saccharomyces Cerevisiae ◽  
First Order ◽  
Metal Biosorption ◽  
Yeast Biomass ◽  
Pseudo First Order

Yeast Saccharomyces cerevisiae biomass was applied for rhenium and accompanying elements (copper and molybdenum) removal from single- and multi-component systems (Re, Re-Mo, Re-Cu, and Re-Mo-Cu). Yeast biomass was characterized using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. The effects of biosorption experimental parameters such as solution pH (2.0–6.0), rhenium concentration (10–100 mg/L), time of interaction (5–120 min), and temperature (20–50 °C) have been discussed in detail. Maximum removal of rhenium (75–84%) and molybdenum (85%) was attained at pH 2.0, while pH 3.0–5.0 was more favorable for copper ions removal (53–68%). The Langmuir, Freundlich, and Temkin isotherm models were used to describe the equilibrium sorption of rhenium on yeast biomass. Langmuir isotherm shows the maximum yeast adsorption capacities toward rhenium ions ranged between 7.7 and 33 mg/g. Several kinetic models (pseudo-first-order, pseudo-second-order, and Elovich) were applied to define the best correlation for each metal. Biosorption of metal ions was well-fitted by Elovich and pseudo-first-order models. The negative free energy reflected the feasibility and spontaneous nature of the biosorption process. Saccharomyces cerevisiae biomass can be considered as a perspective biosorbent for metal removal.

PREPARASI DEINOCOCCUS RADIODURANS DAN KHAMIR DALAM MATERIAL KECAP L-DRYING SEBAGAI BAHAN UJI PROFISIENSI

2016 ◽  
Vol 13 (1) ◽  
pp. 93
Author(s):  
Titin Yulinery ◽  
Ratih M.Dewi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Deinococcus Radiodurans ◽  
Test Preparation ◽  
Quality Parameters ◽  
Soy Sauce ◽  
Yeast Saccharomyces Cerevisiae ◽  
Microbiological Test ◽  
Bacterial Contaminants ◽  
Minimum Number ◽  
Important Quality

Tes kemampuan adalah salah satu kegiatan penting dalam pengendalian mutu dan jaminan kualitas mikrobiologi laboratorium untuk mengukur kompetensi analis dan analisis uji profisiensi membutuhkan persiapan Model mikroorganisme adalah kualitas standar dan validitas. Mikrobiologi uji kualitas produk kedelai utama diarahkan pada kehadiran Saccharomyces cerevisiae ragi (S. cerevisiae), S. Bailli, S. rouxii dankontaminan bakteri seperti Bacillus dan Deinococcus. Jenis ragi dan bakteri yang terlibat dalam proses dan dapat menjadi salah satu parameter kualitas penting dalam persiapan yang dihasilkan. Jumlah dan viabilitas bakteri dan ragi menjadi parameter utama dalam proses persiapan bahan uji. Jumlah tersebut adalah jumlah minimum yang berlaku dapat dianalisis. Jumlah ini harus dibawah 10 CFU diperlukan untuk menunjukkan tingkat hygienitas proses dan tingkat minimal kontaminasi. Viabilitas bakteri dan bahan tes ragi persiapan untuk tes kemahiran kecap yang diawetkan dengan L-pengeringan adalah teknik Deinococcus radiodurans (D. radiodurans) 16 tahun, 58 tahun S. cerevisiae, dan S. roxii 13 tahun. kata kunci: Viabilitas, Deinococcus, khamir, L-pengeringan, Proficiency AbstractProficiency test is one of the important activities in quality control and quality assurance microbiology laboratory for measuring the competence of analysts and analysis Proficiency test requires a model microorganism preparations are standardized quality and validity. Microbiological test of the quality of the main soy products aimed at thepresence of yeast Saccharomyces cerevisiae (S. cerevisiae), S. bailli, S. rouxii and bacterial contaminants such as Bacillus and Deinococcus. Types of yeasts and bacteria involved in the process and can be one of the important quality parameters in the preparation produced. The number and viability of bacteria and yeasts become themain parameters in the process of test preparation materials. The amount in question is the minimum number that is valid can be analyzed. This amount must be below 10 CFU required to indicate the level of hygienitas process and the minimum level of contamination. Viability of bacteria and yeast test preparation materials for proficiencytest of soy sauce that preserved by L-drying technique is Deinococcus radiodurans ( D. radiodurans ) 16 years, 58 years S. cerevisiae, and S. roxii 13 years. key words : Viability, Deinococcus, Khamir, L-drying, Proficiency

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