Search results for "Saccharomyce"

Yeast biomass, an optimised product with myriad applications in the food industry

2015

Abstract Background Yeasts, especially Saccharomyces cerevisiae and related species, have been used by humans since ancient times. In past centuries, the increased demand in yeast-related products has converted yeast biomass into a valuable product, and has forced the generation and optimisation of industrial yeast biomass production processes, which currently generate vast quantities of yeasts yearly. Scope and approach In this article, we review key aspects for the yield first produced empirically, but by also using recent yeast physiology knowledge. We summarise the classical and latest yeasts biomass applications in the food industry, which range from the yeast extract used as an additi…

RHO1(YlRHO1) is a non-essential gene inYarrowia lipolyticaand complementsrho1Δlethality inSaccharomyces cerevisiae

2003

The synthesis of beta-1,3-glucan, the structural component of the yeast cell wall that gives shape to the cell, occurs at the plasma membrane and is the result of the activity of at least a two-component complex. Fks1p is the catalytic subunit directly responsible for the synthesis of beta-1,3-glucan, whilst the second subunit, Rho1p, has a GTP-dependent regulatory role (Yamochi et al., 1994). RHO1 has been characterized in Saccharomyces cerevisiae (Yamochi et al., 1994), and in several other fungal species. In this work, we have used degenerate oligonucleotides derived from the conserved regions of Rho1ps to isolate the RHO1 gene of Yarrowia lipolytica. The gene isolated in this way, which…

Isolation and Characterization of a New Less-Toxic Derivative of the Fusarium Mycotoxin Diacetoxyscirpenol after Thermal Treatment

2011

Trichothecenes are an important class of mycotoxins that act as potent protein synthesis inhibitors in eukaryotic organisms. The compound 4,15-diacetoxyscirpenol is highly toxic for plants and animals. Potatoes are especially prone to be contaminated with 4,15-diacetoxyscirpenol after infection with Fusarium sambucinum. In the current study, the reduction of 4,15-diacetoxyscirpenol during thermal treatment in aqueous solution was monitored. A new derivative was detected and named DAS-M1. After isolation, DAS-M1 was characterized with LC-HR-MS and LC-MS/MS and structurally elucidated with (1)H, (13)C, and 2D NMR. Potatoes were inoculated with F. sambucinum, and the infected potatoes were coo…

Ciclohexadespipeptide beauvericin degradation by different strains of Saccharomyces cerevisiae

2013

Abstract The interaction between the mycotoxin beauvericin (BEA) and 9 yeast strains of Saccharomyces cerevisiae named LO9, YE-2, YE5, YE-6, YE-4, A34, A17, A42 and A08 was studied. The biological degradations were carried out under aerobic conditions in the liquid medium of Potato Dextrose Broth (PDB) at 25 °C for 48 h and in a food/feed system composed of corn flour at 37 °C for 3 days, respectively. BEA present in fermented medium and corn flour was determined using liquid chromatography coupled to the mass spectrometry detector in tandem (LC–MS/MS) and the BEA degradation products produced during the fermentations were determined using the technique of the liquid chromatography coupled …

Reduction of the enniatins A, A1, B, B1 by an in vitro degradation employing different strains of probiotic bacteria: Identification of degradation p…

2013

Abstract The degradation of the Fusarium mycotoxins ENs by 9 bacterial strains characteristic of the gastrointestinal tract like Bb. longum , Bb. bifidum , Bb. breve , Bb. adolescentes , Lb. rhamnosus , Lb. casei–casei , S. termofilus , Lb. ruminis , Lb. casei and twenty two strains of Saccharomyces cerevisiae was studied. The fermentations were carried out in the liquid medium of De Man Rogosa Sharpe (MRS) under anaerobic conditions for Bifidobacteria Streptococcus and Lactobacillus, and in Potato Dextrose Broth (PDB) for Saccharomyces strains, during 48 h. The degradation of the bioactive compounds ENs was also studied in a food system composed by wheat flour naturally contaminated by ENs…

Degradation of the minor Fusarium mycotoxin beauvericin by intracellular enzymes of Saccharomyces cerevisiae

2013

Abstract Beauvericin (BEA) is a cyclic depsipeptide with antibiotic and insecticidal effects. It was discovered for the first time from the fungus Beauveria bassiana , but more significantly, is produced by several Fusarium strains, and considered a contaminant of several cereals like corn, wheat and barley. This study investigated the degradation of BEA by intracellular raw enzymes of four strains of Saccharomyces cerevisiae , named LO9, YE5, A34, and A17. The BEA at 25 mg/kg in a model solution and in corn flour was co-incubated with the raw enzymes from the four yeast strains, respectively. The reduction of BEA was evaluated using liquid chromatography coupled to a diode array detector (…

GC-MS as a tool to study the aromatic profiles of Candida zemplinina/ Saccharomyces cerevisiae mixed fermentation wines

2013

Regulated expression and phosphorylation of the 23-26-kDa ras protein in the sponge Geodia cydonium.

1990

We have cloned, sequenced and examined the sponge Geodia cydonium cDNA encoding a protein homologous to ras proteins. The sponge ras protein has a more conserved N-terminal region and a less conserved C-terminal region, especially in comparison to Dictyostelium discoideum; the similarity to human c-Ha-ras-1 and to Saccharomyces cerevisiae is less pronounced. The sponge ras cDNA comprises five TAG triplets; at the translational level these UAG termination codons are suppressed by a Gln-tRNA. The sponge ras protein was isolated and partially purified (23-26 kDa) and found to undergo phosphorylation at a threonine moiety, when dissociated cells were incubated in the presence of a homologous ag…

Ras-pathway has a dual role in yeast galactose metabolism

2007

AbstractIn the yeast Saccharomyces cerevisiae the genes involved in galactose metabolism (GAL1,7,10) are transcriptionally activated more than a 1000-fold in the presence of galactose as the sole carbon source in the culture media. In the present work, we monitored the activity of the GAL10 gene promoter in different Ras-cAMP genetic backgrounds. We demonstrate that overexpression of C-terminus of the nucleotide exchange factor Cdc25p stimulates GAL10 transcription in yeast strains carrying the contemporary deletion of both RAS genes. Moreover, the deletion of the chromosomal CDC25 gene provokes impaired growth on galactose based media in yeast strain lacking both RAS genes and adenylate cy…

Sch 9p kinase and the Gcn4p transcription factor regulate glycerol production during winemaking

2017

Grape juice fermentation is a harsh environment with many stressful conditions, and Saccharomyces cerevisiae adapts its metabolism in response to those environmental challenges. Many nutrient-sensing pathways control this feature. The Tor/Sch9p pathway promotes growth and protein synthesis when nutrients are plenty, while the transcription factor Gcn4p is required for the activation of amino acid biosynthetic pathways. We previously showed that Sch9p impact on longevity depends on the nitrogen/carbon ratio. When nitrogen is limiting, SCH9 deletion shortens chronological life span, which is the case under winemaking conditions. Its deletion also increases glycerol during fermentation, so the…