Search results for "YEAST"
showing 10 items of 792 documents
Cloning and expression of a cDNA copy of the viral K28 killer toxin gene in yeast
1995
The killer toxin K28, secreted by certain killer strains of the yeast Saccharomyces cerevisiae is genetically encoded by a 1.9 kb double-stranded RNA, M-dsRNA (M28), that is present within the cell as a cytoplasmically inherited virus-like particle (VLP). For stable maintenance and replication, M28-VLPs depend on a second dsRNA virus (LA), which has been shown to encode the major capsid protein (cap) and a capsid-polymerase fusion protein (cap-pol) that provides the toxin-coding M-satellites with their transcription and replicase functions. K28 toxin-coding M28-VLPs were isolated, purified and used in vitro for the synthesis of the single-stranded M28 transcript, which was shown to be of pl…
Conservation and functional preservation of agri-food interest yeasts
2018
The use of yeasts in industry is inseparable from their ability to be produced and dehydrated. This dehydration process causes various dysfunctions in yeast cells that affect their functionality and viability. In order to protect yeasts from dehydration, food additives are often used as emulsifiers and antioxidants. However, yeasts are able to produce naturally protective substances, such as glutathione (GSH) and trehalose (TRE). In this context, three non-Saccharomyces (NS) strains, belonging to the different genera and species Torulaspora delbrueckii, Metschnikowia pulcherrima and Lachancea thermotolerans, were studied in this thesis. Despite the great interest aroused by their multiple a…
Evaluation of the Fermentation Dynamics of Commercial Baker’s Yeast in Presence of Pistachio Powder to Produce Lysine-Enriched Breads
2019
The present work was carried out to evaluate the microbiological, physicochemical, and sensory characteristics of fortified pistachio breads. Pistachio powder (5% w/w) was added to flour or semolina and fermented by a commercial baker’s yeast (Saccharomyces cerevisiae). Pistachio powder did not influence the biological leavening of the doughs. The kinetics of pH and total titratable acidity (TTA) during dough fermentation showed that the leavening process occurred similarly for all trials. The concentration of yeasts increased during fermentation and reached levels of 108 CFU/g after 2 h. Pistachio powder decreased the height and softness of the final breads and increased cell density…
Novel yeast extract is superior to colloidal oatmeal in providing rapid itch relief
2020
Background Approximately, 13.5% of the population suffers from chronic itch. Many cosmetic and pharmaceutical treatments for itch are available; however, cosmetic treatments are not reliably effective and most pharmaceutical formulations carry the risk of adverse events with chronic use. Aims Previously, we have reported a novel extraction process of Saccharomyces cerevisiae, that is, Baker's yeast. The extract obtained from the novel process demonstrates superior anti-itch properties compared to other yeast extracts. In our previous study, we demonstrated that, after 30 minutes, the extract significantly reduced itch when compared to a placebo lotion (P = .002). Methods In the present stud…
In vitro activity of fluconazole, voriconazole and caspofungin against clinical yeast isolates.
2007
Predicting the clinical outcome of a systemic mycosis is often a difficult task, especially when microbiological resistance is one of the factors contributing to therapeutic failure. Some of these factors are host-related--e.g. immune state, site and severity of infection, poor compliance to therapy--while others are associated with the drug's characteristics--e.g. dosage, type of compound (fungistatic/fungicidal), pharmacokinetic properties and drug-drug interactions. In the last few years, clinicians have been confronted with the problem of selecting the most appropriate antifungal therapy for systemic infections and have highlighted the need for a reliable method to assay the in vitro su…
Hub-Centered Gene Network Reconstruction Using Automatic Relevance Determination
2012
Network inference deals with the reconstruction of biological networks from experimental data. A variety of different reverse engineering techniques are available; they differ in the underlying assumptions and mathematical models used. One common problem for all approaches stems from the complexity of the task, due to the combinatorial explosion of different network topologies for increasing network size. To handle this problem, constraints are frequently used, for example on the node degree, number of edges, or constraints on regulation functions between network components. We propose to exploit topological considerations in the inference of gene regulatory networks. Such systems are often…
Gene Expression Analysis of Cold and Freeze Stress in Baker's Yeast
2002
ABSTRACT We used mRNA differential display to assess yeast gene expression under cold or freeze shock stress conditions. We found both up- and down-regulation of genes, although repression was more common. We identified and sequenced several cold-induced genes exhibiting the largest differences. We confirmed, by Northern blotting, the specificity of the response for TPI1 , which encodes triose-phosphate isomerase; ERG10 , the gene for acetoacetyl coenzyme A thiolase; and IMH1 , which encodes a protein implicated in protein transport. These genes also were induced under other stress conditions, suggesting that this cold response is mediated by a general stress mechanism. We determined the ph…
Effect of a Killer Toxin of Yeast on Eucaryotic Systems
1988
The Saccharomyces cerevisiae killer toxin KT 28, which inhibits sensitive yeasts, was shown to have no effect on several pathogenic fungi or on the protozoan Trichomonas vaginalis. At concentrations of about 0.1 mg/ml, a partial inhibition of the skin pathogenic fungi Trichophyton rubrum and Microsporum canis was observed at pH 6.5. No pharmacological activity was detected in various tests with several animal organs.
Non-Saccharomyces Yeasts nitrogen source preferences: Impact on sequential fermentation and wine volatile compounds profile
2017
International audience; Nitrogen sources in the must are important for yeast metabolism, growth, and performance, and wine volatile compounds profile. Yeast assimilable nitrogen (YAN) deficiencies in grape must are one of the main causes of stuck and sluggish fermentation. The nitrogen requirement of Saccharomyces cerevisiae metabolism has been described in detail. However, the YAN preferences of non-Saccharomyces yeasts remain unknown despite their increasingly widespread use in winemaking. Furthermore, the impact of nitrogen consumption by non-Saccharomyces yeasts on YAN availability, alcoholic performance and volatile compounds production by S. cerevisiae in sequential fermentation has b…
Isolation and characterization of anavirulent Candida albicansyeast monomorphic mutant
2003
Mutagenesis of Candida albicans strain ATCC 26555 with N-methyl-nitro-N-nitrosoguanidine followed by plating on solid yeast nitrogen base-N-acetylglucosamine medium at 37 degrees C yielded colony morphology variants that were characterized as forming smooth colonies, in contrast to the rough colonies formed by the parental strain. One yeast monomorphic mutant, CAL4, was studied in detail. Strain CAL4 is defective in filamentous growth, unable to form hyphae or pseudohyphae in vivo and in vitro. These filamentous structures are not elicited by commonly used external stimuli such as serum. The mutant had no obvious alterations in its mannan, glucan or chitin content. The total quantity of non…