scholarly journals Sensitivity of Yeast to "Killer yeast" Strains.

1978 ◽  
Vol 24 (6) ◽  
pp. 121-124 ◽  
Author(s):  
O. BENDOVÁ ◽  
B. PARDONOVÁ
Keyword(s):  
Killer Yeast ◽  
Yeast Strains

scholarly journals Experimental tests of host-virus coevolution in natural killer yeast strains

2017 ◽  
Vol 30 (4) ◽  
pp. 773-781 ◽  
Author(s):  
M. D. Pieczynska ◽  
R. Korona ◽  
J. A. G. M. De Visser
Keyword(s):  
Natural Killer ◽  
Experimental Tests ◽  
Killer Yeast ◽  
Yeast Strains

scholarly journals Scent of a killer: How killer yeast boost its dispersal

2021 ◽  
Author(s):  
Claudia Buser ◽  
Jukka Jokela ◽  
Oliver Martin
Keyword(s):  
Helper Virus ◽  
Insect Vectors ◽  
Double Stranded Rna ◽  
Killer Yeast ◽  
Yeast Strains ◽  
Killer Yeasts ◽  
Host Odor ◽  
Vector Borne ◽  
Dsrna Viruses ◽  
New Habitats

Vector-borne parasites often manipulate hosts to attract uninfected vectors. For example, parasites causing malaria alter host odor to attract mosquitoes. Here we discuss the ecology and evolution of fruit-colonizing yeast in a tripartite symbiosis – the so-called “killer yeast” system. “Killer yeast” consists of Saccharomyces cerevisiae yeast hosting two double stranded RNA viruses (M satellite dsRNAs, L-A dsRNA helper virus). When both dsRNA viruses occur in a yeast cell, the yeast converts to lethal toxin‑producing “killer yeast” phenotype that kills uninfected yeasts. Yeasts on ephemeral fruits attract insect vectors to colonize new habitats. As the viruses have no extracellular stage, they depend on the same insect vectors as yeast for their dispersal. Viruses also benefit from yeast dispersal as this promotes yeast to reproduce sexually, which is how viruses can transmit to uninfected yeast strains. We tested whether insect vectors are more attracted to killer yeasts than to non‑killer yeasts. In our field experiment, we found that killer yeasts were more attractive to Drosophila than non-killer yeasts. This suggests that vectors foraging on yeast are more likely to transmit yeast with a killer phenotype, allowing the viruses to colonize those uninfected yeast strains that engage in sexual reproduction with the killer yeast. Beyond insights into the basic ecology of the killer yeast system, our results suggest that viruses could increase transmission success by manipulating the insect vectors of their host.

scholarly journals Occurrence of killer yeast strains in industrial and clinical yeast isolates

2008 ◽  
Vol 41 (2) ◽  
Author(s):  
MARCELO E BAEZA ◽  
MARIO A SANHUEZA ◽  
VÍCTOR H CIFUENTES
Keyword(s):  
Killer Yeast ◽  
Yeast Strains

scholarly journals Quantitative analysis of the killer activity of some oenological yeasts. Effect of some additives

OENO One ◽  
2000 ◽  
Vol 34 (3) ◽  
pp. 137
Author(s):  
Sandrine Alfenore ◽  
Marie-Line Délia ◽  
Pierre Strehaiano
Keyword(s):  
Initial Rate ◽  
Atp Release ◽  
Killer Toxin ◽  
Sensitive Strain ◽  
Killer Activity ◽  
Killer Yeast ◽  
Killer Strain ◽  
Yeast Strains ◽  
Sterile Medium ◽  
Method Of Evaluation

<p style="text-align: justify;">The Killer factor was discovered in 1963. Since this time it has been widely studied and nowadays a lot is known about genetics of the factor, the biochemistry of the toxin and also about the way of action of the toxin on sensitive yeasts. The yeast strains are classified in three groups : killer strains, sensitive strains and neutral strains. The killer strain is able to kill sensitive strains while neutral strains are unable to kill any strain and remain unaffected by the toxin. Certainly this classification depends on the couple of strains (killer and sensitive) taken as references. It has been clearly established that the toxin acts on the sensitive cells by inducing important losses of ATP : due to holes created by the toxin in the cell membrane, ATP leaves the cell.</p><p style="text-align: justify;">In the field of Enology, it’s generally accepted that a killer yeast has more probabilities to have a good implantation in a non sterile medium (as the must is) than a neutral or a sensitive strain. Nevertheless, it is difficult to have a precise idea of the sensitivity of a strain as well as of its toxicity, as most of the methods are only able to give a qualitative information.</p><p style="text-align: justify;">In this paper, a new method of evaluation of the killer effect is presented. Also some results dealing with its application to the classification of some enological yeast strains are given and discussed.</p><p style="text-align: justify;">This method is based on the measurement of the ATP released by the sensitive strain under the action of the killer toxin. The criterion that we define is the initial rate of ATP release, that means the quantity of ATP lost in the two first hours by the sensitive cells in contact with the toxin. In a first step, it is shown that this method is reliable and also that it is in a good agreement with the method using the flow cytometry. ATP leak could be correlated with the amount of affected cells (dead and damaged cells). So, using this method, it becomes possible to classify easily yeast strains with respect to their sensitivity or toxicity. Several killer yeast strains were tested against a sensitive strain and different sensitive strains were submitted to the action of a killer toxin produced by a killer strain. It was shown that the losses of ATP were quite different according to the sensitivity of the strain. The initial rate of ATP release was found to be in a range of 0.00 to 0.12 micromole/L/h. The second part of the work deals with the study of the possible effect of some products used for winemaking on the efficiency of the killer effect. The products we have studied were bentonite, tannic acid and enological tannins. It is shown that these products may interact with the killer effect. So, bentonite, for example is able to inhibit completely the efficiency of the killer toxin, as soon as its concentration is about 10 grams/hL.</p>

Effect of ethanol, temperature and pH on the stability of killer yeast strains

1992 ◽  
Vol 12 (3) ◽  
pp. 163-168 ◽  
Author(s):  
S. Michalčáková ◽  
Ľ. Repová
Keyword(s):  
Killer Yeast ◽  
Yeast Strains ◽  
The Stability

Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple

2018 ◽  
Vol 39 (4) ◽  
pp. 474-482
Author(s):  
Hoang Thi Le Thuong ◽  
Nguyen Quang Hao ◽  
Tran Thi Thuy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Ph ◽  
Yeast Strains ◽  
Biological Studies ◽  
Taxonomic Characterization

Eight yeast strains (denoted as D1 to D8) were isolated from samples of natural fermented pineapple. Strain D8 showed highest alcoholic production at low pH and special aroma of pineapple has been chosen for further study. Taxonomic characterization of strain D8 using morphological, biochemical and molecular biological studies confirmed that strain D8  belong to Saccharomycetaceae family, Saccharomycetales order and Saccharomyces cerevisiae species. Therefore, we named this strain as Saccharomyces cerevisiae D8 for further study on Brandy production from pineapple. Citation: Hoang Thi Le Thuong, Nguyen Quang Hao, Tran Thi Thuy, 2017. Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple. Tap chi Sinh hoc, 39(4): 474- 482. DOI: 10.15625/0866-7160/v39n4.10864.*Corresponding author: [email protected] Received 5 December 2016, accepted 12 August 2017

Characteristics of ethanol yeast strains in production conditions under higher mash solids concentration conditions

2019 ◽  
Vol 7 (12) ◽  
pp. 121-127
Author(s):  
Taras Lysak ◽  
◽  
Serhii Oliinichuk ◽  
Olha Koval ◽  
◽  
...  
Keyword(s):  
Yeast Strains ◽  
Solids Concentration ◽  
Production Conditions
Sign in / Sign up

Export Citation Format

Share Document