Adaptation of the Yeast S. Cerevisiae Y-503, S. Cerevisiae Daw-3a, S. Oviformis M-12x to Various Ethanol Values. Solid Growth Media

Author(s):  
Eslanda A. Халилова Э.А. ◽  
Elvira A. Islammagomedova ◽  
Svetlana Ts. Kotenko ◽  
Aida A. Abakarova ◽  
Dinara A. Aliverdieva

The paper considers information on the determinants of the viability of yeast cultures cultivated in the form of gi-ant colonies on solid agar under various conditions of ethanol stress. Yeast strains tends to show higher viability along with slow growth. The effect of various concentrations of ethanol (6, 12, 18 %), glucose (20 %) on the morpho-physiological properties of the yeast S. cerevisiae Y-503, S. cerevisiae DAW-3a and S. oviformis M-12X is revealed. It has been determined that Y-503 and DAW-3a are most resistant to ethanol and osmotic stress. The antagonistic inter-action of several stressors most clearly affected the tolerance of the strains to all positions with “ethanol + glucose”. Phenotypic studies have found that the strains survival strategy in adverse conditions in the form of resistance to potassium tellurite inhibitor (K2TeO3) in Y-503, to a greater extent in M-12X. A need for DAW-3a for inositol, ornithine, and lysine was detected; M-12X – sorbitol, inositol. The strains are unsusceptible to synthetic broad-spectrum antimycotics - ketoconazole and fluconazole. However, antibiotic nystatin inhibited their growth, and a high sensitivity of strain M-12X was noted to a greater extent. A comparative analysis of the morphophysiological parameters of cells and giant colonies of the studied strains determined the advantage of polyploid Y-503 in survival and tolerance to the effects of various types of stress. The results can be applied in scientific research and biotechnology for various purposes, based on the use of stress-resistant S. cerevisiae yeast.

2016 ◽  
Vol 73 (10) ◽  
pp. 2436-2445 ◽  
Author(s):  
Samir Mahgoub ◽  
Costas Tsioptsias ◽  
Petros Samaras

The ability of selected manganese peroxidase (MnP) yeast strains, isolated from the mixed liquor of an activated sludge bioreactor treating melanoidins wastewater, was investigated in this work, aiming to examine the degradation potential of melanoidins, in the presence or absence of nutrients. Ten yeast strains were initially isolated from the mixed liquor; four yeast strains (Y1, Y2, Y3 and Y4) were selected for further studies, based on their tolerance towards synthetic melanoidins (SMs) degradation and MnP activity onto solid agar medium. The Y1 strain exhibited almost 98% homology to Candida glabrata yeast, based on 28S rRNA identification studies. During experiments carried out using SM at 30 °C, the four isolated yeast cultures showed a noticeable organic matter reduction and decolorization capacity reaching up to 70% within 2–5 days. However, the corresponding yeast cultures grown in glucose peptone yeast extract medium using real melanoidin wastewater at 30°C showed lower organic matter and color removal capacity, reaching about 60% within 2–5 days. Nevertheless, it was found that the removal of real and synthetic melanoidins could be carried out by these strains under non-aseptic conditions, without requiring further addition of nutrients.


Author(s):  
Elizabeth Moore ◽  
Denis R. Headon

Research indicates that certain yeast strains are beneficial in their capacity to stimulate key microbial populations. This stimulation is strain specific with similar yeast strains exerting their effect on totally different microbial populations. Future yeast culture supplements may contain mixtures of different strains designed to suit specific diets. This, therefore, requires the development of a rapid sensitive technique to differentiate among taxonomically similar yeast strains in animal diets. This technique, termed the Randomly Amplified Polymorphic DNA (RAPD) assay, is based upon the use of randomly designed short polynucleotide primers to amplify genetic sequences from the DNA of the desired yeast strain. Our objective involves the development of this technique to distinguish between closely related yeast strains present in feed. The feed sample investigated was a standard cattle ration containing three strains of Saccharomyces cerevisiae (1026, 2045 and 2020) and Candida utilis 3001 at a concentration of 106 CFU/g respectively. Isolation of single colonies of yeast strains present was achieved by feed extraction in dilution buffer followed by plating a series of dilutions on rose-bengal agar. Thirty randomly selected colonies were cultured in YPD (1% yeast extract, 2% peptone, 2% glucose) broth for 24 - 30 hours at 30°C. Genomic DNA was isolated from yeast cells by standard methods based on subjection of the cells to vortex mixing in the presence of glass beads, triton X-100, sodium dodecyl sulphate, phenol and chloroform. Isolated DNA from randomly selected colonies was amplified by Polymerase Chain Reaction (PCR) for 45 cycles of 1 min at 94°C, 1 min at 36°C and 1 min at 72°C using randomly designed 10 bp primers.


1998 ◽  
Vol 1998 ◽  
pp. 74-74
Author(s):  
D G Chapple ◽  
H F Grundy ◽  
K P A Wheeler ◽  
S P Marsh

There is increasing consumer resistance to feeding antibiotic performance enhancers to beef cattle which has created interest in the use of yeast cultures as an alternative. Yeast cultures such as Diamond V ‘XP’ (Rumenco) are produced by growing selected yeast strains (on a semi-solid medium under stressed conditions) which are then dried. Yeast cultures are now used in a considerable number of North American beef feed lots. The objective of this work was to evaluate the effect of feeding ‘XP’ Yeast to finishing beef cattle on a typical UK grass silage-based diet.


2019 ◽  
Vol 107 (1) ◽  
Author(s):  
Sofia Cividini ◽  
Spyros Sfenthourakis ◽  
Giuseppe Montesanto

AbstractThe capability of producing sounds and vibrations is well known in insects and is thought to be a form of intra- and interspecific communication. Sounds and vibrations are used and modulated for several aims such as interacting with conspecifics, getting information from the environment, and defending against predators. This phenomenon is less known but also present in other arthropods, including a few roller-type terrestrial isopods. In this study, we used a Y-shape test apparatus to investigate the behavior of adult individuals of Armadillo officinalis Duméril, 1816 (Crustacea: Isopoda: Oniscidea) when exposed to two particular vibrational stimuli, namely species-specific stridulations and non-specific substrate-borne vibrations. Our results showed that adults of A. officinalis significantly react to the presence of both types of vibrational stimuli, by moving away from the vibrational source as if they experienced these vibrations as a sign of danger or disturbance. A. officinalis can produce stridulations only when it rolls into a ball during the so-called conglobation, a possible defense mechanism against predators. Stridulation might thus be a secondary form of defense used during conglobation to deter a predator following contact with it and might be experienced as an alert by conspecifics nearby. The high sensitivity to non-specific substrate-borne vibrations might provide A. officinalis with the possibility to anticipate dangers and adverse conditions, giving it a better chance of survival.


2011 ◽  
Vol 78 (2) ◽  
pp. 385-392 ◽  
Author(s):  
Chiemi Noguchi ◽  
Daisuke Watanabe ◽  
Yan Zhou ◽  
Takeshi Akao ◽  
Hitoshi Shimoi

ABSTRACTModern sake yeast strains, which produce high concentrations of ethanol, are unexpectedly sensitive to environmental stress during sake brewing. To reveal the underlying mechanism, we investigated a well-characterized yeast stress response mediated by a heat shock element (HSE) and heat shock transcription factor Hsf1p inSaccharomyces cerevisiaesake yeast. The HSE-lacZactivity of sake yeast during sake fermentation and under acute ethanol stress was severely impaired compared to that of laboratory yeast. Moreover, the Hsf1p of modern sake yeast was highly and constitutively hyperphosphorylated, irrespective of the extracellular stress. SinceHSF1allele replacement did not significantly affect the HSE-mediated ethanol stress response or Hsf1p phosphorylation patterns in either sake or laboratory yeast, the regulatory machinery of Hsf1p is presumed to function differently between these types of yeast. To identify phosphatases whose loss affected the control of Hsf1p, we screened a series of phosphatase gene deletion mutants in a laboratory strain background. Among the 29 mutants, a Δppt1mutant exhibited constitutive hyperphosphorylation of Hsf1p, similarly to the modern sake yeast strains, which lack the entirePPT1gene locus. We confirmed that the expression of laboratory yeast-derived functionalPPT1recovered the HSE-mediated stress response of sake yeast. In addition, deletion ofPPT1in laboratory yeast resulted in enhanced fermentation ability. Taken together, these data demonstrate that hyperphosphorylation of Hsf1p caused by loss of thePPT1gene at least partly accounts for the defective stress response and high ethanol productivity of modern sake yeast strains.


1996 ◽  
Vol 1996 ◽  
pp. 75-75 ◽  
Author(s):  
P. Rowlinson ◽  
S.P. Marsh ◽  
C. Tufnell ◽  
W. Taylor

There is considerable interest in the effect of dietary supplementation with probiotics or yeast cultures on diary cow performance. Yeast cultures such as Diamond V 'XP' are produced by growing selected yeast strains on a semi-solid medium under stressed conditions, which are then dried. Yeast cultures are now used by a majority of the high yielding herds in North America (McCullough 1995). The objective of this work was to evaluate the effect of feeding 'XP' Yeast to a moderate-high yielding (X, 6800kg) herd of dairy cows fed a typical UK diet based on grass silage.72 recently calved Holstein-Friesian dairy cows were allocated to one of two dietary treatments on which they remained throughout 150 days of winter feeding. Both groups received ad libitum grass silage which had a Dry Matter of 224 g/Kg, an estimated ME of 10.8 MJ/Kg DM and a Crude Protein (CP) of 156 g/Kg DM.


1933 ◽  
Vol 16 (4) ◽  
pp. 579-592 ◽  
Author(s):  
Otto Rahn ◽  
Margaret Noble Barnes

Different criteria of death have been compared experimentally and quantitatively. Pure cultures of a yeast have been subjected to adverse conditions, and the number of dead cells, judged by different tests, has been determined in successive time intervals. The yeast cultures were exposed to heat, to HgCl2, to ultraviolet light, and to x-rays. In each case, the cells lost the power of reproduction (measured by the plate count) most rapidly. The loss of fermentation (measured by the CO2 pressure) was less rapid. Still slower was the change in staining reaction with methylene blue, and the loss of selective permeability of the plasma membrane (measured by the percentage of cells staining with Congo red). Slowest of all was the coagulation of protoplasm as observed in the dark-field. In the case of death by heat or by HgCl2, the rate of loss of reproduction was about twice as rapid as that of the loss of fermentation, about three times that of the loss of semipermeability, and about forty times as large as the rate of coagulation. With ultraviolet light and with x-rays, these ratios were decidedly different. The technique employed does not permit the conclusion that any one criterion of death is the prerequisite for other criteria. It does not appear probable that loss of reproduction is the prerequisite for loss of fermentation or of semipermeability because the ratios of the velocities of these processes are not the same with all causes of death. There is no evidence that cells may show certain criteria of death immediately after exposure, and recover later.


2020 ◽  
Vol 246 (11) ◽  
pp. 2299-2307
Author(s):  
Monika Cioch-Skoneczny ◽  
Paweł Satora ◽  
Szymon Skoneczny ◽  
Aneta Pater

Abstract The international competitiveness of the wine sector and consumer demands for the unique wine styles pose challenges in improving the fermentation process. The basis of proper alcoholic fermentation is knowledge about how individual yeast strains interact with the aroma, taste and color of wine, what results in possibility to select species used as starter cultures. To use the value of non-Saccharomyces yeast strains in wine production and to minimize the possibility of wine deterioration, it is necessary to precisely recognize the yeast cultures present on the fruit of the vine and in grape must, as well as their metabolic properties. The aim of the study was to determine the oenological properties of yeasts isolated from spontaneously fermented grape musts obtained from cool climate grapes. For this purpose, Zweigelt grape must was fermented with yeast monocultures. Alcohol, extract, sugars, glycerol, total acidity and free amine nitrogen were analyzed in the obtained wines. Poor fermentation properties of yeast strains results in obtaining wines with relatively large amounts of residual sugars and low alcohol. A decrease in overall acidity was noted in sets with the participation of M. pulcherrima MG971264, while in other tests the opposite trend was observed. Although some microorganisms have the ability to assimilate organic acids found in wine, they are not able to carry out fermentation or they do it inefficiently. Solution to this problem may, therefore, be use of mixed cultures of noble and non-Saccharomyces yeast, what effectively reduce the concentration of organic acids, while not adversely affecting the organoleptic characteristics of the drink.


2020 ◽  
Vol 65 (6) ◽  
pp. 1099-1106
Author(s):  
М.В. Волкова ◽  
◽  
В.В. Бояринцев ◽  
А.В. Трофименко ◽  
С.А. Бирюков ◽  
...  

Quantitative analysis of cytokines, chemokines, growth factors and other soluble proteins in different biological liquids is routinely performed in contemporary diagnostics and biomedicine research. However, current methods of analysis are time-consuming and include multiple steps. In this study, we have developed a protocol that describes how bio-layer interferometry can be applied to quantify an analyte in several minutes. Conditioned growth media collected from mouse mesenchymal stem cells grown in normoxia or hypoxic conditions in a monolayer fashion, MSC-derived 3D cell sheets and 3D spheroids were used as a model system in which we determined a concentration of vascular endothelial growth factor (VEGF-A). This technique displayed a high sensitivity (down to 0.1 ng of VEGF-A per mL as a minimum). The measured concentrations of VEGF-A in the conditioned media from mesenchymal stem cells turned out to be similar with values determined by the enzyme-linked immunosorbent assay. Using bio-layer interferometry, it was shown that as compared to mesenchymal stem cells grown in monolayer, spheroids and 3D sheets of mesenchymal stem cells produce significantly more VEGF-A (by 2.5-3.0-fold). Thus, due to the developed protocol it was possible to adapt bio-layer interferometry for rapid quantification of growth factors in conditioned media.


Sign in / Sign up

Export Citation Format

Share Document