Search results for "yeast"
showing 10 items of 792 documents
Saccharomyces uvarum is responsible for the traditional fermentation of apple chicha in Patagonia
2016
Apple chicha is a fresh low alcoholic beverage elaborated by aboriginal communities of Andean Patagonia (Argentina and Chile). In the present work, we identified the yeast microbiota associated with this fermentation, and characterized genetically those belonging to the genus Saccharomyces. Both Saccharomyces cerevisiae and S. uvarum were found in the analyzed fermentations. Phylogenetic and population structure analyses based on genes sequence analysis were carried out for both S. cerevisiae and S. uvarum strains obtained in this study and a set of additional strains from diverse origins. The results demonstrate that S. cerevisiae strains from apple chicha belong to the big group of wine/E…
Microorganism adhesion using silicon dioxide: An experimental study
2020
In this study, spectrophotometry was used to measure changes in the absorbance properties of yeast, Gram-positive, and Gram-negative bacteria after their attachment to silicon dioxide microparticles (silica). The goal of this study was to determine whether spectrophotometry is an effective method to distinguish these microorganisms from one another and determine whether they have an affinity for silicon dioxide. The experiments were performed by examining the light absorption properties of yeast, Gram-positive and Gram-negative bacteria in a spectrophotometer, both with and without silicon dioxide microparticles. The experiments produced a number of promising results. First, the spectrophot…
Anhydrobiosis in yeast: Glutathione overproduction improves resistance to dehydration of a recombinant Ogataea (Hansenula) polymorpha strain
2018
Abstract We show for the first time that a recombinant strain of yeast Ogataea (Hansenula) polymorpha is at least as tolerant to dehydration-rehydration treatment as the wild type strain. It is believed that this unusual characteristic of this recombinant yeast strain is linked with its ability to overproduce glutathione. Based on plasma membrane permeability analysis, we hypothesise that glutathione, in addition to its powerful antioxidative protective effects on membrane lipids, may also protect membrane proteins and/or nucleic acids. The combination of yeast cell dehydration with immobilisation and subsequent preliminary slow rehydration in water vapour gave good results in terms of reco…
One-Cell Doubling Evaluation by Living Arrays of Yeast, ODELAY!
2016
Abstract Cell growth is a complex phenotype widely used in systems biology to gauge the impact of genetic and environmental perturbations. Due to the magnitude of genome-wide studies, resolution is often sacrificed in favor of throughput, creating a demand for scalable, time-resolved, quantitative methods of growth assessment. We present ODELAY (One-cell Doubling Evaluation by Living Arrays of Yeast), an automated and scalable growth analysis platform. High measurement density and single-cell resolution provide a powerful tool for large-scale multiparameter growth analysis based on the modeling of microcolony expansion on solid media. Pioneered in yeast but applicable to other colony formin…
Yeast thioredoxin reductase Trr1p controls TORC1-regulated processes
2018
The thioredoxin system plays a predominant role in the control of cellular redox status. Thioredoxin reductase fuels the system with reducing power in the form of NADPH. The TORC1 complex promotes growth and protein synthesis when nutrients, particularly amino acids, are abundant. It also represses catabolic processes, like autophagy, which are activated during starvation. We analyzed the impact of yeast cytosolic thioredoxin reductase TRR1 deletion under different environmental conditions. It shortens chronological life span and reduces growth in grape juice fermentation. TRR1 deletion has a global impact on metabolism during fermentation. As expected, it reduces oxidative stress tolerance…
Dom34 Links Translation to Protein O-mannosylation.
2016
In eukaryotes, Dom34 upregulates translation by securing levels of activatable ribosomal subunits. We found that in the yeast Saccharomyces cerevisiae and the human fungal pathogen Candida albicans, Dom34 interacts genetically with Pmt1, a major isoform of protein O-mannosyltransferase. In C. albicans, lack of Dom34 exacerbated defective phenotypes of pmt1 mutants, while they were ameliorated by Dom34 overproduction that enhanced Pmt1 protein but not PMT1 transcript levels. Translational effects of Dom34 required the 5′-UTR of the PMT1 transcript, which bound recombinant Dom34 directly at a CA/AC-rich sequence and regulated in vitro translation. Polysomal profiling revealed that Dom34 stimu…
Effects of innovative and conventional sanitizing treatments on the reduction of Saccharomycopsis fibuligera defects on industrial durum wheat bread
2016
Wickerhamomyces anomalus, Hyphopichia burtonii and Saccharomycopsis fibuligera are spoilage yeasts causing chalk mold defects on sliced bread packaged under modified atmosphere. The first objective of this study, carried out in a bread-making company for two consecutive years, was to genetically identify yeasts isolated from spoiled sliced bread in Modified Atmosphere Packaging (MAP) and to determine the dominant species among identified strains. The second objective was to evaluate the effects of hydrogen peroxide and silver solution 12% (HPS) treatment in the leavening cells and cooling chambers, in comparison with the conventional Ortho-Phenylphenol (OPP) fumigating treatment, on the inc…
Molecular Methods for Identification of Wine Microorganisms and Yeast Development
2017
A prerequisite for the biochemical and physiological investigation of microorganisms is the isolation and management of pure cultures. Nevertheless, most of the environmental microorganisms are graded as “yet not cultivable” because the nutritional requirements are unknown or they could not be isolated due to the fact that fast-growing strains overgrow other microorganisms of a microbiota. In addition to plating techniques, isolation without cultivation and analysis of microbes could be performed by micromanipulation techniques or the application of optical tweezers followed by the utilization of PCR-based technologies.
Functional Genomics in Wine Yeast: DNA Arrays and Next Generation Sequencing
2017
Since their very beginning, DNA array and next-generation sequencing technologies have been used with Saccharomyces cerevisiae cells. In the last 7 years, an increasing number of studies have focused on the study of wine strains and winemaking. The uncovering of the genomic features of these strains and expression profiles under the different stressful conditions that they have to deal with have contributed significantly to the knowledge of how this amazing microorganism can convert grape must into a drink that has enormously influenced mankind for 7000 years.This review presents a synopsis of DNA array and next-generation sequencing (NGS) technologies and focus mainly in their use in study…
Evolution of yeast populations during different biodynamic winemaking processes
2016
This work was performed to evaluate the evolution of indigenous yeasts during wine productions carried out following the principles of biodynamic agriculture. Five trials were designed with different technological interventions consisting of the addition of nitrogen (in the form of ammonium salt), thiamine salt, oxygen, and pied de cuvee at varying concentrations. Yeasts were estimated by haemocytometer chamber and plate counts and identified by sequencing of the D1/D2 domain of the 26S rRNA gene. The isolates identified as Saccharomyces cerevisiae were found to dominate must fermentations and were genetically differentiated by interdelta sequence analysis (ISA). Several non-Saccharomyces s…