Search results for "YEAST"
showing 10 items of 792 documents
The elemental role of iron in DNA synthesis and repair
2017
Iron is an essential redox element that functions as a cofactor in many metabolic pathways. Critical enzymes in DNA metabolism, including multiple DNA repair enzymes (helicases, nucleases, glycosylases, demethylases) and ribonucleotide reductase, use iron as an indispensable cofactor to function. Recent striking results have revealed that the catalytic subunit of DNA polymerases also contains conserved cysteine-rich motifs that bind iron–sulfur (Fe/S) clusters that are essential for the formation of stable and active complexes. In line with this, mitochondrial and cytoplasmic defects in Fe/S cluster biogenesis and insertion into the nuclear iron-requiring enzymes involved in DNA synthesis a…
The cytochrome system in mitochondria of unfertilized sea urchin eggs
1958
Abstract 1. 1. The cytochrome system of unfertilized sea urchin eggs has been studied using preparations of isolated mitochondria. 2. 2. The difference spectra of isolated mitochondria show the presence of a complete and operating cytochrome system formed by the cytochromes a , a 3 , b and c . 3. 3. This cytochrome system is very similar to that of mammals and yeast as demonstrated by spectrophotometric and manometric experiments.
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…
Mannoproteins from the cell wall ofKluyveromyces lactis
1986
Wall mannoproteins from Kluyveromyces lactis have been solubilised by treatment of cell walls with sodium dodecyl sulphate (SDS) or zymolyase. While the former reagent liberates a large number of molecular species, zymolyase preferentially releases a high-molecular-weight material that is sensitive to endo-β-N-acetylglucosaminidase H, and a 29-kDa molecule that reacts with the antiserum raised against a similar species from walls of Saccharomyces cerevisiae. In contrast with observations on isolated walls of S. cerevisiae, dithiothreitol pretreatment of K. lactis walls does not enhance the effect of zymolyase upon mannoprotein release. However, the action of thiol agents is still necessary …
Dairy yeasts produce milk protein-derived antihypertensive hydrolysates
2013
Abstract The potential of 20 dairy yeast strains belonging to Debaryomyces hansenii , Kluyveromyces lactis and Kluyveromyces marxianus species was examined for the production of milk protein-derived antihypertensive hydrolysates. For this purpose yeast strains were grown in microbiological medium with casein or lactoferrin as sole nitrogen source, and the inhibitory effects of casein and lactoferrin hydrolysates (CSHs and LFHs) on angiotensin I-converting enzyme (ACE) activity were determined. Based on the ACE-inhibitory activity, four CSHs and five LFHs were selected, and permeate fractions with molecular masses lower than 3 kDa (pCSHs and pLFHs) were obtained. In vitro ACE-inhibitory pote…
Microbial Dynamics between Yeasts and Acetic Acid Bacteria in Kombucha: Impacts on the Chemical Composition of the Beverage.
2020
Kombucha is a traditional low-alcoholic beverage made from sugared tea and transformed by a complex microbial consortium including yeasts and acetic acid bacteria (AAB). To study the microbial interactions and their impact on the chemical composition of the beverage, an experimental design with nine couples associating one yeast strain and one AAB strain isolated from original black tea kombucha was set up. Three yeast strains belonging to the genera Brettanomyces, Hanseniaspora, and Saccharomyces and three strains of Acetobacter and Komagataeibacter species were chosen. Monocultures in sugared tea were analyzed to determine their individual microbial behaviors. Then, cultivation of the ori…
Microbiological and technological parameters impacting the chemical composition and sensory quality of kombucha
2020
International audience; Kombucha is a beverage made from sugared tea transformed by yeasts and acetic acid bacteria. Being originally homemade, it has become an industrially produced soft drink whose quality standards are poorly defined and whose production process is still not fully controlled. Based on current knowledge in beverages, links between kombucha's chemical composition and sensorial compounds are drawn. Macromolecules create turbidity, whereas uncharacterized tea pigments derivatives participate in the color. Residual sugars bring sweetness and organic acids produced by acetic acid bacteria form its characteristic sour taste. Acetic acid is also part of its aroma profile, althou…
Alpha-1-antitrypsin-induced inhibition of complement-dependent phagocytosis.
1981
Abstract In a previous investigation, inhibition of complement-dependent rosette formation by alpha1-antitrypsin (α1-AT) was observed, and it was demonstrated that α1-AT interacts through its carbohydrate portion with C3 and its fragments. In the present study, the effect of α1-AT on the complement-receptor-mediated phagocytosis by human peripheral blood monocytes was examined. Purified α1-AT inhibited in a dose-dependent manner phagocytosis of C3-carrying yeast particles. Inhibition was selective, concerned only C3-receptor-mediated phagocytosis, neither Fc-receptor-mediated phagocytosis nor uptake of untreated yeast particles was blocked by α1-AT. It was demonstrated that α1-AT exerted it…
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…
Heat shock response in yeast involver changes in both transcription rates and mRNA stabilities
2011
We have analyzed the heat stress response in the yeast Saccharomyces cerevisiae by determining mRNA levels and transcription rates for the whole transcriptome after a shift from 25uC to 37uC. Using an established mathematical algorithm, theoretical mRNA decay rates have also been calculated from the experimental data. We have verified the mathematical predictions for selected genes by determining their mRNA decay rates at different times during heat stress response using the regulatable tetO promoter. This study indicates that the yeast response to heat shock is not only due to changes in transcription rates, but also to changes in the mRNA stabilities. mRNA stability is affected in 62% of …