scholarly journals Improved Leavening Ability of a Wild Yeast, Saccharomyces cerevisiae AK46 2-deoxyglucose Resistant Mutant

2015 ◽  
Vol 21 (4) ◽  
pp. 623-630 ◽  
Author(s):  
Dai Mikumo ◽  
Masahiro Takaya ◽  
Yoshitake Orikasa ◽  
Takuji Ohwada
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Resistant Mutant ◽  
Wild Yeast ◽  
Leavening Ability

Isolation and characterization of an uncoupler-resistant mutant of Saccharomyces cerevisiae

1984 ◽  
Vol 8 (7) ◽  
pp. 507-516 ◽  
Author(s):  
Charles-Henri Dupont ◽  
Roland Caubet ◽  
Jean-Pierre Mazat ◽  
Bernard Guerin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Resistant Mutant ◽  
Isolation And Characterization

8-Azaguanine Resistant Mutant of the Yeast,Saccharomyces cerevisiae

1986 ◽  
Vol 50 (5) ◽  
pp. 1339-1340
Author(s):  
Naoko Sato ◽  
Makoto Shimosaka ◽  
Yasuki Fukuda ◽  
Kousaku Murata ◽  
Akira Kimura
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Resistant Mutant ◽  
Yeast Saccharomyces Cerevisiae

scholarly journals A heat shock-resistant mutant of Saccharomyces cerevisiae shows constitutive synthesis of two heat shock proteins and altered growth.

1984 ◽  
Vol 99 (4) ◽  
pp. 1441-1450 ◽  
Author(s):  
H Iida ◽  
I Yahara
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Type Strain ◽  
Wild Type Strain ◽  
Growth Control ◽  
Protein S ◽  
Resistant Mutant ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Sulfur Starvation

A heat shock-resistant mutant of the budding yeast Saccharomyces cerevisiae was isolated at the mutation frequency of 10(-7) from a culture treated with ethyl methane sulfonate. Cells of the mutant are approximately 1,000-fold more resistant to lethal heat shock than those of the parental strain. Tetrad analysis indicates that phenotypes revealed by this mutant segregated together in the ratio 2+:2- from heterozygotes constructed with the wild-type strain of the opposite mating type, and are, therefore, attributed to a single nuclear mutation. The mutated gene in the mutant was herein designated hsr1 (heat shock response). The hsr1 allele is recessive to the HSR1+ allele of the wild-type strain. Exponentially growing cells of hsr1 mutant were found to constitutively synthesize six proteins that are not synthesized or are synthesized at reduced rates in HSR1+ cells unless appropriately induced. These proteins include one hsp/G0-protein (hsp48A), one hsp (hsp48B), and two G0-proteins (p73, p56). Heterozygous diploid (hsr1/HSR1+) cells do not synthesize the proteins constitutively induced in hsr1 cells, which suggests that the product of the HSR1 gene might negatively regulate the synthesis of these proteins. The hsr1 mutation also led to altered growth of the mutant cells. The mutation elongated the duration of G1 period in the cell cycle and affected both growth arrest by sulfur starvation and growth recovery from it. We discuss the problem of which protein(s) among those constitutively expressed in growing cells of the hsr1 mutant is responsible for heat shock resistance and alterations in the growth control.

scholarly journals Optimization of the cultivation conditions of indigenous wild yeasts and evaluation of their leavening capacity

2019 ◽  
Author(s):  
Elsa Beyene Gebreslassie ◽  
Anteneh T. Tefera ◽  
Diriba Muleta ◽  
Solomon K. Fantaye ◽  
Gary M. Wessel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Hydrogen Sulfide ◽  
Cell Mass ◽  
Baker’S Yeast ◽  
Fermented Foods ◽  
Baker's Yeast ◽  
Leavening Ability ◽  
Maximum Cell ◽  
Commercial Yeast ◽  
Indigenous Yeasts

AbstractEthiopia has a high demand for baker’s yeast in the bread and beverage industries. Unfortunately, Ethiopia has no producing plant for baker’s yeast and instead relies on costly imports. The objective of this work was to identify the most productive and useful indigenous baker’s yeasts isolated from local fermented foods and drinks, honey and Molasses using leavening ability as the major metric. Six of the test isolates produced a maximum cell mass at 30°C, pH of 5.5 and 48 hours of incubation. Isolate AAUTf1 did not produce hydrogen sulfide, while isolates AAUTf5, AAUTj15 and AAUSh17 produced low levels of this chemical, and isolates AAUMl20 and AAUWt21 produced high levels of hydrogen sulfide, neglecting their utility in baking. The leavening performance of isolates AAUTf1 (Candida humilis) and AAUTf5 (Kazachstania bulderi) had the highest dough volume of 131 cm3and 128 cm3respectively in 120 min. Isolates AAUSh17 (Saccharomyces cerevisiae) and AAUTj15 (Saccharomyces cerevisiae) raised the dough volume of 127 cm3and 125 cm3respectively, at 60 min compared to commercial yeast (117 cm3in 90 min). The study also revealed that mixed cultures of indigenous yeasts had better leavening capacity than single cultures. The co-inoculated cultures of AAUTf1 + AAUTf5 + AAUTj15, AAUTf5 + AAUTj15, and AAUTf1 + AAUTj15 + AAUSh17 reached 143 cm3at 90 min, 141 cm3and 140 cm3both at 60 min, respectively. Thus, the indigenous isolates are candidates for optimizing utilization of yeast for fast promotion and utilization in the bakery industries.

scholarly journals Ability of Saccharomyces cerevisiae MC87-46 to assimilate isomaltose and its effects on sake taste

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Seitaro Tsutsumi ◽  
Mai Mochizuki ◽  
Kiyota Sakai ◽  
Akane Ieda ◽  
Reiji Ohara ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Genomic Dna ◽  
Dianthus Caryophyllus ◽  
Resistant Mutant ◽  
Commercial Application ◽  
Transporter Gene ◽  
Nutrient Profile ◽  
Wild Strains ◽  
Organic Acids And Sugars

Abstract Recently, wild strains of Saccharomyces cerevisiae isolated from a variety of natural resources have been used to make bread, beer, wine, and sake. In the current study, we isolated wild S. cerevisiae MC strain from the carnation (Dianthus caryophyllus L) flower and produced sake using its cerulenin-resistant mutant strain MC87-46. Then, we characterized the components, including ethanol, amino acids, organic acids, and sugars, in the fermented sake. Sake brewed with MC87-46 is sweet owing to the high content of isomaltose, which was at a concentration of 44.3 mM. The low sake meter value of −19.6 is most likely due to this high isomaltose concentration. The genomic DNA of MC87-46 encodes for isomaltases IMA1, IMA2, IMA3, IMA4 and IMA5, as well as the isomaltose transporter gene, AGT1. However, these genes were not induced in MC87-46 by isomaltose, and the strain did not possess isomaltase activity. These results show that MC87-46 cannot utilize isomaltose, resulting in its accumulation in the fermented sake. Isomaltose concentrations in sake brewed with MC87-46 were 24.6-fold more than in commercial sake. These findings suggest that MC87-46 may be useful for commercial application in Japanese sake production because of its unique flavour and nutrient profile.

scholarly journals Golden wine produced from mixed juices of passion fruit (Passiflora edulis), mango (Mangifera indica) and pineapple (Ananas comosus)

2014 ◽  
Vol 14 (64) ◽  
pp. 9104-9116
Author(s):  
FD Nzabuheraheza ◽  
◽  
AN Nyiramugwera ◽  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Specific Gravity ◽  
Mangifera Indica ◽  
Sugar Content ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Ananas Comosus ◽  
Alcohol Content ◽  
Passiflora Edulis ◽  
Wild Yeast

An attempt to produce yellow/golden wine was done in the laboratory using a mixture of fruits (3 3.3% each) as golden must extracted from Passiflora edulis (passion fruit ), Mangifera indica (mango) and Ananas comosus (pineapple ). After extraction of three juices, physic al and chemical parameters were determined before and during fermentation of the must. These parameters were: wild yeast colony forming units per milliliter (CFU/ml) of fermenting must, total soluble solids (degrees Brix) , pH, alcohol content, titratable acidity in percent , fermentation temperature, sugar content (g/l) , and specific gravity. The fermentation of a mixture of juices was done at room temperature, i.e., at 22 o C, and the wild yeast used was Saccharomyces cerevisiae , a strain called “musanzeensis” isolated from local traditional banana wine. During substantial must fermentation, the pH decreased from 5.5 for fresh juice to 3.2 for wine, total soluble solids from 20 o Brix to 2 o Brix, titratable acidity increased from 0.68% to 1.4%, sugar content decreased from 85 g/l to 32 g/l, specific gravity decreased from 1.040 to 1.002, yeast growth increased from 3 to 18 log CFU/ml, and alcohol content increased from 0.0 to 12% alcohol by volume. After twelve days of fermentation, the color of wine remained yellow, the flavor was enhanced, sweetness diminished and the acidity (sourness) increased slightly. These chemical changes could be due to the Saccharomyces cerevisiae activity , which was characterized by a remarkable foam and intensive production of carbon dioxide in the fermenting wine . The mixture of the three juices from Passiflora edulis, Mangifera indica and Ananas comosus produced an alcoholic beverage with a wonderful flavor that was generally delicious and acceptable to 40 trained and blind panelists during sensory evaluation using as 9 –point Hedonic scale. Each panelist sipped once 100ml of sample taken from wine. Thus, the obtained yellow wine should be promoted for adding value to local fruits, imported wine reduction, job creation, income generation and rural development.

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