scholarly journals SELECTION OF THE TECHNOLOGICAL PARAMETERS OF FERMENTATION OF HIGH-CONCENTRATION WORT WITH OSMOPHILIC YEAST RACES FOR OBTAINING BIOETHANOL

2021 ◽  
Vol 15 (3) ◽  
Author(s):  
S. Kovalchuk ◽  
T. Mudrak
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dry Matter ◽  
Raw Materials ◽  
Yeast Cells ◽  
Technological Parameters ◽  
High Concentration ◽  
Yeast Saccharomyces Cerevisiae ◽  
Ph Values ◽  
Dry Matter Concentration ◽  
Cell Synthesis

Bioethanol production is a key issue that helps meet the growing demand for energy resources and ensure a sustainable economy. A promising direction is producing bioethanol by using the technology of fermentation of high-concentration wort obtained from the dry matter of grain raw materials. The purpose of this work is researching osmophilic races of distiller’s yeast under the conditions of fermentation of high-concentration wort at increased acidity. Selective breeding of a new strain of the yeast Saccharomyces cerevisiae DO-16 has allowed obtaining ethanol producers able to ferment grain wort with the dry matter concentration 24–34% at pH 6.0–3.0, with alcohol accumulation in the fermented wash up to 17% vol.  It has been studied how the pH of wort affects the dynamics of yeast cell synthesis by the distiller’s yeast races Saccharomyces cerevisiae DO-11 and Saccharomyces cerevisiae DO-16. It has been established that at the pH values 2.5, 3.0, 3.5, and 4.0, the concentration of yeast cells in the race Saccharomyces cerevisiae DO-16 was higher by 2.6, 1.7, 1.5, and 1.4 times respectively, as compared with Saccharomyces cerevisiae DO-11. It has been found that culturing industrial yeast of these races at low pH values ​​will provide not only the required sterility of the substrate, but also a high content of yeast cells, which is 250–320 million/cm³. The chemical and technological parameters of the fermented wash obtained by using the yeast races Saccharomyces cerevisiae DO-11 and DO-16 at the wort concentration 20–34% DM have been studied. It has been found that under all research conditions, the yeast of the race Saccharomyces cerevisiae DO-16 synthesised more ethanol than the strain Saccharomyces cerevisiae DO-11 did. The use of a new high-productive strain of Saccharomyces cerevisiae DO-16 will allow fermenting wort with a high ethanol concentration in the wash. It will also reduce the consumption of heat expended on isolating alcohol from the wash and of water expended on cooling, and lessen the amount of post-alcohol stillage.

scholarly journals THE EFFECT OF THE INTENSITY OF AERATING THE MEDIUM ON THE METABOLIC ACTIVITY OF ALCOHOL YEAST

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
L. Levandovsky ◽  
М. Kravchenko
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metabolic Activity ◽  
Anaerobic Fermentation ◽  
Raw Materials ◽  
Modern Technology ◽  
Higher Alcohols ◽  
Great Decrease ◽  
Technological Parameters ◽  
Secondary Products ◽  
Yeast Saccharomyces Cerevisiae

The article presents the results of investigating how the intensity of aerating the medium effects on the cultivation process and the metabolic activity of alcoholic yeast Saccharomyces cerevisiae, strain U-563, in the modern technology of alcohol and baking yeast from molasses. The chemical and technological parameters of media at the aerobic and anaerobic stages of the process, the level of accumulation of the major and secondary products of yeast metabolism, and their enzymatic activity have been determined by methods commonly employed in science and in the practice of alcohol biotechnology. The objects of research were the yeast Saccharomyces cerevisiae, molasses wort, the medium in the process of yeast cultivation, and fermented wash. It has been established that two factors are the most important in the accumulation of alcoholic yeast biomass: the intensity of aerating the medium, and the staged introduction of the substrate during biomass cultivation. The more aerated the medium, the more intensively secondary metabolites of yeast Saccharomyces cerevisiae are formed (glycerol, aldehydes, higher alcohols, volatile acids, and esters) – both at the yeast generation stage and during anaerobic fermentation. When yeast Saccharomyces cerevisiae is grown in a gradient-continuous manner in a battery of series-connected apparatuses, with undiluted substrate (molasses) added by degrees, yeast biosynthesis is significantly enhanced compared to the traditional homogeneous-continuous method. The results obtained indicate the active metabolism of carbohydrates in the Krebs cycle, when the medium is intensively aerated. Besides, the results reveal the high reactivity of aldehydes and esters that results in their transformation into other compounds, and in a great decrease in their amount at the anaerobic stage of the process. However, a progressive increase is observed in glycerol, higher alcohols, and volatile acids, starting from the first yeast generator and up to the last fermentation apparatus, irrespective of the level of aerating the medium during yeast cultivation. These findings can be effectively used to manufacture food, technical, and fuel ethanol industrially from sugar-based raw materials in the course of co-production of alcohol and baking yeast.

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.

scholarly journals INFLUENCE OF DRY CONCENTRATION OF DRY SUBSTANCES ON FEATURES OF OSMOPHILIC ALCOHOLIC RACES OF YEAST

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
S. Kovalchuk ◽  
T. Mudrak
Keyword(s):  
Dry Matter ◽  
Raw Materials ◽  
Experimental Studies ◽  
Physiological Characteristics ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Size And Shape ◽  
Dry Matter Concentration ◽  
High Concentrations ◽  
Matter Concentration

The main factors influencing the cultivation environment on the growth and development of different races of alcoholic yeast have been studied. The following races were selected for studies of the influence of wort dry matter concentration on morpho-physiological features of alcoholic yeast yeast cells: S. cerevisiae ДО–16, ДО–11, K-81, XII. The novelty of the work lies in the study of the influence of the concentration of dry matter of the wort on the morpho-physiological features of alcoholic yeast, screening of alcoholic races for fermentation of highly concentrated wort. The morphology of cells of alcoholic races of the yeast S. cerevisiae, which are cultured on starch-containing medium, has been insufficiently studied. It was found that the cells of the alcoholic yeast race S. cerevisiaeДО-16 and ДО-11 had smaller cell sizes in comparison with the thermotolerant and mesophilic races S. cerevisiae K-81 and XII at a concentration of DM wort of 28%. However, the number of yeast cells in S. cerevisiae ДО-16 and ДО-11 races is higher. During the fermentation of highly concentrated wort, these indicators characterize the increase in the working surface of the yeast in the fermented medium, which allows to intensify the fermentation process. Studies have been conducted on the effect of dry matter concentration on the size and shape of giant colonies of alcoholic races of yeast. Culture samples were taken in the stationary phase of growth. Studies of giant colonies of alcoholic breeds of yeast cultured on wort at a concentration of 28% DM indicate that the race of S. cerevisiae ДО-16, in comparison with other races, is able to withstand high concentrations of wort. After all, the size and shape of the giant colonies of this race indicate that the yeast cells were in a satisfactory physiological condition. According to morpho-physiological characteristics, alcoholic yeast of race S. cerevisiae ДО–16, ДО–11, K–81, XII with thermotolerant and osmophilic properties for fermentation of highly concentrated wort was screened Based on theoretical and experimental studies, it was found that the selected race of yeast S. cerevisiae ДО-16 on morpho-physiological characteristics has advantages over races ДО-11, K-81, XII for fermentation of high concentrations of wort. Thus, for fermentation of highly concentrated wort from grain raw materials, a highly productive race of alcoholic yeast with increased osmophilicity - S. cerevisiae ДО –16 was selected.

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.  

scholarly journals Pulsed Electric Field (PEF) Enhances Iron Uptake by the Yeast Saccharomyces cerevisiae

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 850
Author(s):  
Karolina Nowosad ◽  
Monika Sujka ◽  
Urszula Pankiewicz ◽  
Damijan Miklavčič ◽  
Marta Arczewska
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electric Field ◽  
Metal Ion ◽  
Treatment Time ◽  
Control Sample ◽  
Pulsed Electric Field ◽  
Yeast Cells ◽  
Iron Ions ◽  
Metal Ion Binding ◽  
Yeast Saccharomyces Cerevisiae

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 μs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.

The Cloning and Mapping of ADR6, a Gene Required for Sporulation and for Expression of the Alcohol Dehydrogenase II Isozyme From Saccharomyces cerevisiae

Genetics ◽  
1987 ◽  
Vol 116 (4) ◽  
pp. 531-540
Author(s):  
Aileen K W Taguchi ◽  
Elton T Young
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcohol Dehydrogenase ◽  
Single Gene ◽  
Carbon Sources ◽  
Transcription Unit ◽  
Yeast Cells ◽  
Recessive Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Upstream Activating Sequence ◽  
A Site

ABSTRACT The alcohol dehydrogenase II (ADH2) gene of the yeast, Saccharomyces cerevisiae, is not transcribed during growth on fermentable carbon sources such as glucose. Growth of yeast cells in a medium containing only nonfermentable carbon sources leads to a marked increase or derepression of ADH2 expression. The recessive mutation, adr6-1, leads to an inability to fully derepress ADH2 expression and to an inability to sporulate. The ADR6 gene product appears to act directly or indirectly on ADH2 sequences 3' to or including the presumptive TATAA box. The upstream activating sequence (UAS) located 5' to the TATAA box is not required for the Adr6- phenotype. Here, we describe the isolation of a recombinant plasmid containing the wild-type ADR6 gene. ADR6 codes for a 4.4-kb RNA which is present during growth both on glucose and on nonfermentable carbon sources. Disruption of the ADR6 transcription unit led to viable cells with decreased ADHII activity and an inability to sporulate. This indicates that both phenotypes result from mutations within a single gene and that the adr6-1 allele was representative of mutations at this locus. The ADR6 gene mapped to the left arm of chromosome XVI at a site 18 centimorgans from the centromere.

Identification of an upstream activating sequence and an upstream repressible sequence of the pyruvate kinase gene of the yeast Saccharomyces cerevisiae

1989 ◽  
Vol 9 (2) ◽  
pp. 442-451
Author(s):  
M Nishizawa ◽  
R Araki ◽  
Y Teranishi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Pyruvate Kinase ◽  
Transcriptional Activation ◽  
Regulatory Elements ◽  
Noncoding Region ◽  
Yeast Cells ◽  
Kinase Gene ◽  
Yeast Saccharomyces Cerevisiae ◽  
Upstream Activating Sequence

To clarify carbon source-dependent control of the glycolytic pathway in the yeast Saccharomyces cerevisiae, we have initiated a study of transcriptional regulation of the pyruvate kinase gene (PYK). By deletion analysis of the 5'-noncoding region of the PYK gene, we have identified an upstream activating sequence (UASPYK1) located between 634 and 653 nucleotides upstream of the initiating ATG codon. The promoter activity of the PYK 5'-noncoding region was abolished when the sequence containing the UASPYK1 was deleted from the region. Synthetic UASPYK1 (26mer), in either orientation, was able to restore the transcriptional activity of UAS-depleted mutants when placed upstream of the TATA sequence located at -199 (ATG as +1). While the UASPYK1 was required for basal to intermediate levels of transcriptional activation, a sequence between -714 and -811 was found to be necessary for full activation. On the other hand, a sequence between -344 and -468 was found to be responsible for transcriptional repression of the PYK gene when yeast cells were grown on nonfermentable carbon sources. This upstream repressible sequence also repressed transcription, although to a lesser extent, when glucose was present in the medium. The possible mechanism for carbon source-dependent regulation of PYK expression through these cis-acting regulatory elements is discussed.

INTERCONVERSION OF YEAST MATING TYPES II. RESTORATION OF MATING ABILITY TO STERILE MUTANTS IN HOMOTHALLIC AND HETEROTHALLIC STRAINS

Genetics ◽  
1977 ◽  
Vol 85 (3) ◽  
pp. 373A-393
Author(s):  
James B Hicks ◽  
Ira Herskowitz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Yeast Cells ◽  
Mating Types ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Mating Ability ◽  
Mating Type Locus ◽  
Regulatory Information ◽  
Ho Gene

ABSTRACT The two mating types of the yeast Saccharomyces cerevisiae can be interconverted in both homothallic and heterothallic strains. Previous work indicates that all yeast cells contain the information to be both a and α and that the HO gene (in homothallic strains) promotes a change in mating type by causing a change at the mating type locus itself. In both heterothallic and homothallic strains, a defective α mating type locus can be converted to a functional a locus and subsequently to a functional α locus. In contrast, action of the HO gene does not restore mating ability to a strain defective in another gene for mating which is not at the mating type locus. These observations indicate that a yeast cell contains an additional copy (or copies) of α information, and lead to the "cassette" model for mating type interconversion. In this model, HM  a and hmα loci are blocs of unexpressed α regulatory information, and HMα and hm  a loci are blocs of unexpressed a regulatory information. These blocs are silent because they lack an essential site for expression, and become active upon insertion of this information (or a copy of the information) into the mating type locus by action of the HO gene.

The immunosuppressant FK506 inhibits amino acid import in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (8) ◽  
pp. 5010-5019 ◽  
Author(s):  
J Heitman ◽  
A Koller ◽  
J Kunz ◽  
R Henriquez ◽  
A Schmidt ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Amino Acid ◽  
Cyclosporin A ◽  
Secretory Pathway ◽  
Yeast Cells ◽  
Amino Acid Transporters ◽  
Yeast Saccharomyces Cerevisiae ◽  
Eukaryotic Microorganisms

The immunosuppressants cyclosporin A, FK506, and rapamycin inhibit growth of unicellular eukaryotic microorganisms and also block activation of T lymphocytes from multicellular eukaryotes. In vitro, these compounds bind and inhibit two different types of peptidyl-prolyl cis-trans isomerases. Cyclosporin A binds cyclophilins, whereas FK506 and rapamycin bind FK506-binding proteins (FKBPs). Cyclophilins and FKBPs are ubiquitous, abundant, and targeted to multiple cellular compartments, and they may fold proteins in vivo. Previously, a 12-kDa cytoplasmic FKBP was shown to be only one of at least two FK506-sensitive targets in the yeast Saccharomyces cerevisiae. We find that a second FK506-sensitive target is required for amino acid import. Amino acid-auxotrophic yeast strains (trp1 his4 leu2) are FK506 sensitive, whereas prototrophic strains (TRP1 his4 leu2, trp1 HIS4 leu2, and trp1 his4 LEU2) are FK506 resistant. Amino acids added exogenously to the growth medium mitigate FK506 toxicity. FK506 induces GCN4 expression, which is normally induced by amino acid starvation. FK506 inhibits transport of tryptophan, histidine, and leucine into yeast cells. Lastly, several genes encoding proteins involved in amino acid import or biosynthesis confer FK506 resistance. These findings demonstrate that FK506 inhibits amino acid import in yeast cells, most likely by inhibiting amino acid transporters. Amino acid transporters are integral membrane proteins which import extracellular amino acids and constitute a protein family sharing 30 to 35% identity, including eight invariant prolines. Thus, the second FK506-sensitive target in yeast cells may be a proline isomerase that plays a role in folding amino acid transporters during transit through the secretory pathway.

GRR1 of Saccharomyces cerevisiae is required for glucose repression and encodes a protein with leucine-rich repeats

1991 ◽  
Vol 11 (10) ◽  
pp. 5101-5112
Author(s):  
J S Flick ◽  
M Johnston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Interactions ◽  
Tandem Repeats ◽  
Glucose Repression ◽  
Molecular Data ◽  
Primary Response ◽  
Yeast Cells ◽  
Cell Fractionation ◽  
Protein Protein Interactions ◽  
Yeast Saccharomyces Cerevisiae

Growth of the yeast Saccharomyces cerevisiae on glucose leads to repression of transcription of many genes required for alternative carbohydrate metabolism. The GRR1 gene appears to be of central importance to the glucose repression mechanism, because mutations in GRR1 result in a pleiotropic loss of glucose repression (R. Bailey and A. Woodword, Mol. Gen. Genet. 193:507-512, 1984). We have isolated the GRR1 gene and determined that null mutants are viable and display a number of growth defects in addition to the loss of glucose repression. Surprisingly, grr1 mutations convert SUC2, normally a glucose-repressed gene, into a glucose-induced gene. GRR1 encodes a protein of 1,151 amino acids that is expressed constitutively at low levels in yeast cells. GRR1 protein contains 12 tandem repeats of a sequence similar to leucine-rich motifs found in other proteins that may mediate protein-protein interactions. Indeed, cell fractionation studies are consistent with this view, suggesting that GRR1 protein is tightly associated with a particulate protein fraction in yeast extracts. The combined genetic and molecular data are consistent with the idea that GRR1 protein is a primary response element in the glucose repression pathway and is required for the generation or interpretation of the signal that induces glucose repression.

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