The impact of transcription factors Znf1, Sip4, Adr1, Tup1, and Hap4 on xylose alcoholic fermentation in the engineered yeast Saccharomyces cerevisiae

Author(s):  
Ljubov Dzanaeva ◽  
Barbara Kruk ◽  
Justyna Ruchala ◽  
Andriy Sibirny ◽  
Kostyantyn Dmytruk
2007 ◽  
Vol 73 (8) ◽  
pp. 2432-2439 ◽  
Author(s):  
Carole Guillaume ◽  
Pierre Delobel ◽  
Jean-Marie Sablayrolles ◽  
Bruno Blondin

ABSTRACT Fructose utilization by wine yeasts is critically important for the maintenance of a high fermentation rate at the end of alcoholic fermentation. A Saccharomyces cerevisiae wine yeast able to ferment grape must sugars to dryness was found to have a high fructose utilization capacity. We investigated the molecular basis of this enhanced fructose utilization capacity by studying the properties of several hexose transporter (HXT) genes. We found that this wine yeast harbored a mutated HXT3 allele. A functional analysis of this mutated allele was performed by examining expression in an hxt1-7Δ strain. Expression of the mutated allele alone was found to be sufficient for producing an increase in fructose utilization during fermentation similar to that observed in the commercial wine yeast. This work provides the first demonstration that the pattern of fructose utilization during wine fermentation can be altered by expression of a mutated hexose transporter in a wine yeast. We also found that the glycolytic flux could be increased by overexpression of the mutant transporter gene, with no effect on fructose utilization. Our data demonstrate that the Hxt3 hexose transporter plays a key role in determining the glucose/fructose utilization ratio during fermentation.


1993 ◽  
Vol 50 (3) ◽  
pp. 484-489 ◽  
Author(s):  
L.E. Gutierrez

A study was carried out in order to determine the effect of vitamins (biotin, thiamine, pantotheniic acid and pyridoxal) and micronutrient (zinc, boron, manganese and iron) deficiencies on higher alcohol production during alcoholic fermentation with the industrially used yeast Saccharomyces cerevisiae M-300-A. Zinc deficiency induced a reduction on the levels of isobutyl and isoamyl alcohols. An increase on isobutyl alcohol (fivefold) and a reduction of isoamyl alcohol (two fold) and n-propyl alcohol (three fold) contents resulted from pantotheiiic acid deficiency, whereas pyridoxal deficiency caused an increase on the levels of isobutyl and isoamyl alcohols. Biotin was not essential for the growth of this strain.


1997 ◽  
Vol 17 (1) ◽  
pp. 69-80 ◽  
Author(s):  
I V Karpichev ◽  
Y Luo ◽  
R C Marians ◽  
G M Small

Expression of the POX1 gene, which encodes peroxisomal acyl coenzyme A oxidase in the yeast Saccharomyces cerevisiae, is tightly regulated and can be induced by fatty acids such as oleate. Previously we have shown that this regulation is brought about by interactions between trans-acting factor(s) and an upstream activating sequence (UAS1) in the POX1 promoter. We recently identified and isolated a transcription factor, Oaf1p, that binds to the UAS1 of POX1 and mediates its induction. A screening strategy has been developed and used to identify eight S. cerevisiae mutants, from three complementation groups, that are defective in the oleate induction of POX1. Characterization of one such mutant led to the identification of Oaf2p, a protein that is 39% identical to Oaf1p. Oaf1p and Oaf2p form a protein complex that is required for the activation of POX1 and FOX3 and for proliferation of peroxisomes. We propose a model in which these two transcription factors heterodimerize and mediate this activation process. The mutants that we have isolated, and further identification of the corresponding defective genes, provide us with an opportunity to characterize the mechanisms involved in the coordinate regulation of peroxisomal beta-oxidation enzymes.


Author(s):  
T. V. Meledina ◽  
V. A. Ivanova ◽  
H. Razan ◽  
O. V. Golovinskaya ◽  
I. V. Novikova ◽  
...  

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.


Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 67
Author(s):  
Fatma Bouaziz ◽  
Amal Ben Abdeddayem ◽  
Mohamed Koubaa ◽  
Francisco J. Barba ◽  
Khawla Ben Jeddou ◽  
...  

This study investigates the feasibility of producing ethanol from date palm seeds. The chemical compositions of three varieties of date seeds were first studied, showing mainly the presence of cellulose and hemicellulose. Ethanol was produced after a pre-treatment of date seeds using acid hydrolysis to extract the cellulosic fraction and to remove the lignin. Producing ethanol by fermentation was performed using the yeast Saccharomyces cerevisiae for 24 h, during which ethanol yield, biomass concentration, and total reducing sugars were recorded. The results obtained showed that the sugar content decreased over time, while ethanol production increased. Indeed, date seeds gave the highest ethanol concentration of 21.57 g/L after 6 h of alcoholic fermentation. These findings proved the feasibility of producing ethanol from date seeds.


Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1423
Author(s):  
Stefano Scansani ◽  
Doris Rauhut ◽  
Silvia Brezina ◽  
Heike Semmler ◽  
Santiago Benito

This study investigates the influence of the antimicrobial agent chitosan on a selected Schizosaccharomyces pombe strain during the alcoholic fermentation of ultra-pasteurized grape juice with a high concentration of malic acid. It also studies a selected Saccharomyces cerevisiae strain as a control. The study examines several parameters relating to wine quality, including volatile and non-volatile compounds. The principal aim of the study is to test the influence of chitosan on the final chemical composition of the wine during alcoholic fermentation, and to compare the two studied fermentative yeasts between them. The results show that chitosan influences the final concentration of acetic acid, ethanol, glycerol, acetaldehyde, pyruvic acid, α-ketoglutarate, higher alcohols, acetate esters, ethyl esters, and fatty acids, depending on the yeast species.


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