Search results for "YEAST"
showing 10 items of 792 documents
Comparative genomics to unravel adaptive mechanisms in Saccharomyces
2021
Saccharomyces genus is a fascinating model for evolutionary biology due to its high genetic and phenotypic diversity. The improvement in the sampling efforts during the last decade has resulted in the isolation of Saccharomyces species from a wide range of sources worldwide. S. cerevisiae is probably the most well known eukaryotic system and the dominant organism in most industrial fermentations. Due to the new challenges of the winemaking industry (e.g., global warming and changing customer demands), alternative Saccharomyces species have attracted researchers’ attention during the last decade as a poorly exploited resource of biodiversity. S. kudriavzevii and S. uvarum are two promising c…
An Off-On-Off Fluorescent Sensor for pH Windows Based on the 13aneN4-Zn 2+ System
2016
International audience; The new ligand L was prepared and features a 13-membered tetraaza macrocyclic ring with a 1,8-naphthalimide fluorophore appended to a C atom of its backbone. The protonation constants of L as well as its complexation constants with Zn2+ ions were determined in 1:1 water/methanol solutions by potentiometric titrations. Fluorimetric pH titrations were performed with L alone and L in the presence of Zn2+ ions (1:1), and the species distributions (%) versus pH were compared. A window-shaped fluorescence trend was observed with pH for the L/Zn2+ system, which behaves as an off-on-off pH sensor. The on window is centred in the 6.5-7.5 pH range, in correspondence with the f…
Opracowanie metody oraz optymalizacja warunków immobilizacji inwertazy drożdżowej w żelu alginianowym
2016
Zbadano wpływ różnych stężeń chlorku wapnia oraz czasu kondycjonowania inwertazy drożdżowej (EC 3.2.1.26) izolowanej z drożdży piekarniczych Saccharomyces cerevisiae immobilizowanej w żelu alginianowym. Z wykorzystanych w badaniach różnych stężeń chlorku wapnia (2, 5, 10 i 30%) najwyższą aktywność enzymatyczną uzyskano dla najwyższego wykorzystanego stężenia. Wykazano, że czas 15 minut kondycjonowania żelu alginianowego w chlorku wapnia prowadzi do najefektywniejszego immobilizowania inwertazy. Dodatkowo oceniono wpływ immobilizacji inwertazy drożdżowej na jej aktywność w odniesieniu do wolnej formy tego enzymu w szerokim zakresie pH (3,5; 4,0; 4,5; 5,0; 5,5; 6,0; 6,5) oraz temperatury (21,…
Production and extraction of astaxanthin from Phaffia rhodozyma and its biological effect on alcohol-induced renal hypoxia in Carassius auratus
2015
The effect of astaxanthin (3,3â²-dihydroxy-s-carotene-4,4â²-dione) on alcohol-induced morphological changes in Carassius auratus, as an experimental model, was determined. The yeast Phaffia rhodozyma was used as a source of astaxanthin. The animals were divided into three groups for 30 days: one group was treated with ethanol at a dose of 1.5% mixed in water, the second one with EtOH 1.5% and food enriched with astaxanthin from P. rhodozyma, and the third was a control group. After a sufficient experimental period, the samples were processed using light microscopy and evaluated by histomorphological and histochemical staining, and the data were supported by immunohistochemical analysis, u…
Development of molecular approaches for direct detection and quantification of wine-related microorganisms
2018
En esta tesis doctoral se han desarrollado procedimientos para la detección y cuantificación de levaduras y bacterias acéticas totales y, en concreto, de las especies más importantes en la vinificación como Saccharomyces cerevisiae, Brettanomyces bruxellensis, Zygosaccharomyces bailii, L. plantarum, y O. oeni. Las estrategias que se han utilizado para el desarrollo de nuevos métodos se centran fundamentalmente en la supresión del paso de extracción previa de ADN y de los procedimientos de eliminación de inhibidores de la reacción de PCR presentes en las muestras. Para llevar a cabo este objetivo general, se establecieron los siguientes objetivos específicos; 1, desarrollo de un método de qP…
Sourdough and cereal-based foods: traditional and innovative products
2017
Cereals represent the main crop of the five continents and contribute greatly to the diet of several populations. Cereals often undergo a fermentation before eating. This process is fundamental to confer high sensory quality, as well as to preserve and enhance the nutritional and safety aspects of the resulting products. Fermented cereal based foods are complex microbial ecosystems, mainly represented by lactic acid bacteria and yeasts. Among these products, sourdough is worldwide applied to produce breads. Sourdough technology is also used to improve the final characteristics of fortified and gluten–free breads. This chapter focuses on the use of cereals to produce the most relevant fermen…
Role of Nutraceuticals in Hypolipidemic Therapy.
2015
Nutraceuticals are food components or active ingredients present in foods and used in therapy. This article analyzes the characteristics of the molecules with a lipid-lowering effect. The different nutraceuticals may have different mechanisms of action: inhibition of cholesterol synthesis primarily through action on the enzyme HMG-CoA reductase (policosanol, polyphenols, garlic and, above all, red yeast rice), increase in LDL receptor activity (berberine), reduction of intestinal cholesterol absorption (garlic, plant sterols, probiotics), and also the ability to interfere with bile metabolism (probiotics, guggul). Based on the different mechanisms of action, some nutraceuticals are then abl…
Inhibition of Saccharomyces cerevisiae Pdr5p by a natural compound extracted from Brazilian Red Propolis
2011
Multidrug resistance of cancer cells and pathogenic microorganisms leading to the treatment failure of some forms of cancer or life-threatening bacterial or fungal infections is often caused by the overexpression of multidrug efflux pumps belonging to the ATP-binding cassette transporters superfamily. The multidrug resistance of fungal cells often involves the overexpression of efflux pumps belonging to the pleiotropic drug resistance (PDR) family of ABC transporters. Possibly the best-studied fungal PDR transporter is the multidrug resistance transporter Pdr5p of Saccharomyces cerevisiae. Some research groups have been searching for new inhibitors of these efflux pumps in order to alleviat…
The Influence of Chemical Composition of Commercial Lemon Essential Oils on the Growth of Candida Strains
2013
Candida yeasts are saprophytes naturally present in the environment and forming colonies on human mucous membranes and skin. They are opportunistic fungi that cause severe and even fatal infections in immunocompromised individuals. Several essential oils, including eucalyptus, pine, cinnamon and lemon, have been shown to be effective against Candida strains. This study addresses the chemical composition of some commercial lemon essential oils and their antifungal potential against selected Candida yeast strains. Antifungal potential and minimum inhibitory concentrations were determined for six commercial lemon essential oils against five Candida yeast strains (Candida albicans 31, Candida t…
Función del gen PIR32 en la construcción y biogénesis de la pared celular de Candida albicans
2013
Candida albicans es un hongo que forma parte de la microbiota comensal de los tractos urogenital y gastrointestinal de muchos individuos, no obstante es la especie que se encuentra con mayor frecuencia como patógeno humano y por ello es la más estudiada y utilizada como modelo de investigación con respecto a otras especies; además, la incidencia de infecciones producidas por Candida se ha incrementado en los últimos años observándose paralelamente un aumento significativo de la morbilidad y la mortalidad como consecuencia de estas infecciones. La pared celular es la característica diferencial más importante entre las células eucariotas humanas y fúngicas, lo cual la convierte en diana ideal…