Search results for "RME"
showing 10 items of 6748 documents
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…
Bacterial communities associated with the ectoparasitic mites Varroa destructor and Tropilaelaps mercedesae of the honey bee (Apis mellifera).
2017
Varroa and Tropilaelaps mites have been reported as serious ectoparasites of the honey bee (Apis mellifera). In this study, bacterial communities associated with Varroa destructor and Tropilaelaps mercedesae from northern Thailand were determined, using both culture-dependent and culture-independent approaches. Adult female mites were collected from apiaries in Chiang Mai and Lampang provinces. Culturable bacteria were isolated from individual mites. On average, we observed approximately 1340 and 1140 CFU/mite in Varroa and Tropilaelaps, respectively. All isolates were assigned to the genus Enterococcus. Six samples of genomic DNA from 30-50 mites were extracted and subjected to pyrosequenc…
Dextran production by Lactobacillus sakei MN1 coincides with reduced autoagglutination, biofilm formation and epithelial cell adhesion
2017
40 p.-7 fig.-4 fig.supl.
The impact of fermentation processes on the production, retention and bioavailability of carotenoids: An overview
2020
Abstract Background Carotenoids are isoprenoids compounds widely distributed in foods. A difference of carotenoids relative to other food bioactives is that some can be converted into compounds exhibiting vitamin A activity, which is essential for humans. Besides, they are more versatile as they are also natural pigments, antioxidants and can be involved in health-promoting actions. Lately, they are also attracting interest in relation to skin beauty. Their importance for different industry sector (foods, feeds, pharmaceutical, cosmetics) is therefore indisputable. Carotenoids can be obtained by different approaches including extraction from appropriate sources or synthesis. Scope and appro…
Vitamin D and Cardiovascular Health
2021
The principal source of vitamin D in humans is its biosynthesis in the skin through a chemical reaction dependent on sun exposure. In lesser amounts, the vitamin can be obtained from the diet, mostly from fatty fish, fish liver oil and mushrooms. Individuals with vitamin D deficiency, defined as a serum level of 25 hydroxyvitamin D < 20 ng/dl, should be supplemented. Vitamin D deficiency is a prevalent global problem caused mainly by low exposure to sunlight. The main role of 1,25 dihydroxyvitamin D is the maintenance of calcium and phosphorus homeostasis. However, vitamin D receptors are found in most human cells and tissues, indicating many extra-skeletal effects of the vitamin, particula…
Development of a method for the direct fermentation of semolina by selected sourdough lactic acid bacteria
2016
Three obligately heterofermentative lactic acid bacteria (LAB) strains (Lactobacillus sanfranciscensis PON100336, Leuconostoc citreum PON10079 and Weissella cibaria PON10030) were used in this study as a multi-species starter culture for sourdough production. The starter inoculum was prepared and propagated in sterile semolina extract (SSE) broth. Acidification kinetics, microbiological counts detected on specific media for sourdough LAB, polymorphic profile comparison and species-specific PCRs evidenced a stability of the liquid inoculum over time determining its suitability for direct addition to semolina. In order to validate this innovative method for the production of durum wheat (Trit…
A new fear in wine: Isolation of Staphylococcus epidermidis histamine producer
2016
Abstract Biogenic amines (BAs) are undesirable compounds in all foods and beverages because they may induce food-borne intoxications when consumed at high concentrations. The aim of this study was to identify the organism responsible for the synthesis of histamine in a Tempranillo red wine from Ribera de Duero D.O. (Denomination of origin), Spain. Bacteria present in wines after malolactic fermentation were isolated, identified and typed. Four strains of the species Oenococcus oeni and two strains of Staphylococcus epidermidis were found. None of the O. oeni strains produced histamine, cadaverine or putrescine, but one of the S. epidermidis strains (Pa) was able to produce all three in synt…
Improved detection and enumeration of yeasts in wine by Cells-qPCR
2018
Abstract Quantitative PCR by directly sampling (Cells-qPCR) has been adapted to detect and quantify total yeasts, and B. bruxellensis, S. cerevisiae and Z. bailii species, in grape musts and wines. To increase assay sensitivity, the effects of a previous cell wall lysis, by both enzymatic and mechanical methods, were evaluated. Cell wall disruption by mechanical methods showed the best results to enhance assay sensitivity. Numerous standard curves were constructed by mechanically lysed cells in culture medium, and in white and red grape musts and wines. Good regression values (>0.99) and efficiencies (>0.99) were obtained, and it was possible to detect one single cell per reaction in all th…
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…
On the origins and industrial applications ofSaccharomyces cerevisiae×Saccharomyces kudriavzeviihybrids
2017
Companies based on alcoholic fermentation products, such as wine, beer and biofuels, use yeasts to make their products. Each industrial process utilizes different media conditions, which differ in sugar content, the presence of inhibitors and fermentation temperature. Saccharomyces cerevisiae has traditionally been the main yeast responsible for most fermentation processes. However, the market is changing due to consumer demand and external factors such as climate change. Some processes, such as biofuel production or winemaking, require new yeasts to solve specific challenges, especially those associated with sustainability, novel flavours and altered alcohol content. One of the proposed so…