Search results for " yeast"
showing 10 items of 152 documents
Killer toxin of Hanseniaspora uvarum
1990
The yeast Hanseniaspora uvarum liberates a killer toxin lethal to sensitive strains of the species Saccharomyces cerevisiae. Secretion of this killer toxin was inhibited by tunicamycin, an inhibitor of N-glycosylation, although the mature killer protein did not show any detectable carbohydrate structures. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular killer toxin was precipitated with ethanol and purified by ion exchange chromatography. SDS-PAGE of the electrophoretically homogenous killer protein indicated an apparent molecular mass of 18,000. Additional investigations of the primary toxin binding sites within the cell wall of sensitiv…
Use of sequentially inoculation of Saccharomyces cerevisiae and Hanseniaspora uvarum strains isolated from honey by-products to improve and stabilize…
2022
Mead is a beverage produced by alcoholic fermentation of honey-must. The starter yeasts that are commonly used for the alcoholic fermentation of honey-must are oenological Saccharomyces cerevisiae strains. The objective of the present work was, for the first time, to apply yeasts of honey by-products origin to evaluate the influences the taste-olfactory attributes of mead. For this purpose, three experimental productions were set up, which included: (i) single inoculation of S. cerevisiae; (ii) single inoculation of Hanseniaspora uvarum; (iii) sequential inoculation of H. uvarum/S. cerevisiae. Two control trials were performed, using a commercial strain of S. cerevisiae of oenological origi…
Yeast ecology of vineyards within Marsala wine area (western Sicily) in two consecutive vintages and selection of autochthonous Saccharomyces cerevis…
2012
In this work, the yeast ecology associated with the spontaneous fermentation of Grillo cultivar grapes from 10 vineyards was analyzed from grape harvest till complete consumption of must sugars. The microbiological investigation started with the plate count onto two culture media to distinguish total yeasts (TY) and presumptive Saccharomyces (PS). Yeasts were randomly isolated and identified by a combined genotypic approach consisting of restriction fragment length polymorphism (RFLP) of 5.8S rRNA gene and 26S rRNA and sequencing of D1/D2 domain of the 26S rRNA gene, which resulted in the recognition of 14 species belonging to 10 genera. The distribution of the yeasts within the vineyards s…
Evolution of fermenting microbiota in tarhana produced under controlled technological conditions
2011
PubMedID: 21839387 The purpose of this study was to evaluate the evolution of lactic acid bacteria (LAB) and yeasts during the fermentation of tarhana produced with some pasteurised ingredients and carried out at 30 and 40 °C. The chemical parameters were those typical for tarhana production. Coliform bacteria were not detected during fermentation, while LAB and yeasts were in the range 10 7-10 8 colony forming units (CFU) g -1. Plate counts showed an optimal development of both fermenting microbial groups and the differences in cell concentrations were not significant (P > 0.05). LAB were isolated during fermentation and grouped on the basis of phenotypic and polymorphic characteristics…
Ex situ conservation and exploitation of fungi in Italy
2011
Abstract The kingdom Fungi comprises one of the most diverse groups of living organisms. They are numerous, ubiquitous and undertake many roles both independently and in association with other organisms. Fungi display a wide diversity of forms also mirrored by functional diversity and play such a dominant role in human society that they are arguably biotechnologically the most important group of organisms. Ex situ conservation of fungi, not only guarantees correct management and conservation of biodiversity, but also its exploitation in different fields. This article describes the major biological resource centres dealing with fungi in Italy and gives several examples of fungal exploitation…
Nutraceuticals and Lipid Management
2020
Scientific data support the effectiveness of reducing total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in preventing atherosclerotic disease cardiovascular disease (ASCVD) events. Current guidelines suggest the use of innovative nutritional strategies in lipid management based on consumption of nutraceuticals and functional foods. Nutraceuticals are products isolated or purified from foods (generally sold in medicinal forms), while a functional food is similar in appearance to, or may be, a conventional food. Both nutritional components promote health, lead to better well-being, and reduce risk of cardiovascular disease, possibly by affecting plasma lipid levels. The m…
A phosphorylation cycle shapes gradients of the DYRK family kinase Pom1 at the plasma membrane.
2011
http://linkinghub.elsevier.com/; International audience; Concentration gradients regulate many cell biological and developmental processes. In rod-shaped fission yeast cells, polar cortical gradients of the DYRK family kinase Pom1 couple cell length with mitotic commitment by inhibiting a mitotic inducer positioned at midcell. However, how Pom1 gradients are established is unknown. Here, we show that Tea4, which is normally deposited at cell tips by microtubules, is both necessary and, upon ectopic cortical localization, sufficient to recruit Pom1 to the cell cortex. Pom1 then moves laterally at the plasma membrane, which it binds through a basic region exhibiting direct lipid interaction. …
Peroxisomal beta-oxidation activities and gamma-decalactone production by the yeast Yarrowia lipolytica.
1998
International audience; gamma-Decalactone is a peachy aroma compound resulting from the peroxisomal beta-oxidation of ricinoleic acid by yeasts. The expression levels of acyl-CoA oxidase (gene deletion) and 3-ketoacyl-CoA thiolase activities (gene amplification on replicative plasmids) were modified in the yeast Yarrowia lipolytica. The effects of these modifications on beta-oxidation were measured. Overexpression of thiolase activity did not have any effect on the overall beta-oxidation activity. The disruption of one of the acyl-CoA oxidase genes resulted in an enhanced activity. The enhancement led to an increase of overall beta-oxidation activity but reduced the gamma-decalactone produc…
Metabolomic by 1H NMR Spectroscopy Differentiates “Fiano Di Avellino” White Wines Obtained with Different Yeast Strains
2013
We employed (1)H NMR spectroscopy to examine the molecular profile of a white "Fiano di Avellino" wine obtained through fermentation by either a commercial or a selected autochthonous Saccharomyces cerevisiae yeast starter. The latter was isolated from the same grape variety used in the wine-making process in order to strengthen the relationship between wine molecular quality and its geographical origin. (1)H NMR spectra, where water and ethanol signals were suppressed by a presaturated T1-edited NMR pulse sequence, allowed for definition of the metabolic content of the two differently treated wines. Elaboration of NMR spectral data by multivariate statistical analyses showed that the two d…
Conserved role of Ras-GEFs in promoting aging: from yeast to mice
2011
RasGRF1 is a Ras-guanine nucleotide exchange factor implicated in a variety of physiological processes including learning and memory and glucose homeostasis. To determine the role of RASGRF1 in aging, lifespan and metabolic parameters were analyzed in aged RasGrf1(-/-) mice. We observed that mice deficient for RasGrf1(-/-) display an increase in average and most importantly, in maximal lifespan (20% higher than controls). This was not due to the role of Ras in cancer because tumor-free survival was also enhanced in these animals. Aged RasGrf1(-/-) displayed better motor coordination than control mice. Protection against oxidative stress was similarly preserved in old RasGrf1(-/-). IGF-I lev…