A5037156035- Fungal and yeast genetics research
- Biofuel production and bioconversion
- Microbial Metabolic Engineering and Bioproduction
- Fermentation and Sensory Analysis
- Polysaccharides and Plant Cell Walls
- Enzyme Structure and Function
- Gene Regulatory Network Analysis
- Plant nutrient uptake and metabolism
- Force Microscopy Techniques and Applications
- Enzyme Production and Characterization
- Collembola Taxonomy and Ecology Studies
- Endoplasmic Reticulum Stress and Disease
- Microbial Natural Products and Biosynthesis
- Neurobiology and Insect Physiology Research
- Enzyme Catalysis and Immobilization
- CRISPR and Genetic Engineering
- Nanofabrication and Lithography Techniques
- Hemiptera Insect Studies
- RNA and protein synthesis mechanisms
- Genetics, Aging, and Longevity in Model Organisms
- Mycotoxins in Agriculture and Food
- Bioinformatics and Genomic Networks
- Bacterial Genetics and Biotechnology
- French Urban and Social Studies
- Plant biochemistry and biosynthesis
Delaware State University
2025
Institut National des Sciences Appliquées de Toulouse
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2016-2024
Université de Toulouse
2014-2023
Dendris (France)
2012-2023
Biotechnology Institute
2019-2021
Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés
2011-2020
Laboratoire d'Analyse et d'Architecture des Systèmes
2010-2019
Roche (France)
2010-2019
Real-time RT-PCR is the recommended method for quantitative gene expression analysis. A compulsory step selection of good reference genes normalization. few often referred to as HouseKeeping Genes (HSK), such ACT1, RDN18 or PDA1 are among most commonly used, their assumed remain unchanged over a wide range conditions. Since this assumption very unlikely, geometric averaging multiple, carefully selected internal control now strongly normalization avoid problem variation single genes. The aim...
The polysaccharide composition of the Saccharomyces cerevisiae cell wall was measured under various growth conditions and compared with structure.Chemical enzymatic methods were used to determine levels beta-1,3-glucan 1,6-glucan, mannan chitin yeast wall, whereas structure/resistance qualitatively assessed by sensibility lytic action zymolyase. It found that dry mass polysaccharides content could vary more than 50% nature carbon source, nitrogen limitation, pH, temperature aeration, mode...
A simple and reliable method for the efficient inactivation of metabolism quantitative metabolite extraction from yeast cells is presented. It based on use a boiling solution made 75% ethanol (volume/final volume) buffered with 70 mM-Hepes (final concentration), pH 7.5, to guarantee stability throughout whole procedure large variety metabolites, including all glycolytic intermediates, nucleotides, pyridine nucleotides organic acids compounds. The fast, requiring only 3 min incubation in...
In the yeast Saccharomyces cerevisiae, environmental stress conditions that damage cell wall lead to activation of so-called "compensatory mechanism," aimed at preserving integrity through a remodeling this extracellular matrix. Here we used DNA microarrays investigate molecular basis response two agents induce transient damage; namely Congo Red and Zymolyase. Treatment cells with these elicited up-regulation 132 101 genes respectively, main functional groups among them being involved in...
One of the most powerful techniques for attributing functions to genes in uni- and multicellular organisms is comprehensive analysis mutant traits. In this study, systematic quantitative analyses traits are achieved budding yeast Saccharomyces cerevisiae by investigating morphological phenotypes. Analysis fluorescent microscopic images triple-stained cells makes it possible treat variations as Deletion nearly half not essential growth affects these Similar phenotypes caused deletions...
It is well known that glycogen and trehalose accumulate in yeast under nutrient starvation or entering into the stationary phase of growth, high levels are found heat-shocked cells. However, effects various types stress on trehalose, especially glycogen, poorly documented. Taking account almost all genes encoding enzymes involved metabolism these two reserve carbohydrates contain between one several copies stress-responsive element (STRE), an investigation was made possibility a link...
Perturbations of the yeast cell wall trigger a repair mechanism that reconfigures its molecular structure to preserve integrity. To investigate this mechanism, we compared global gene expression in five mutant strains, each bearing mutation (i.e. fks1, kre6, mnn9, gas1, and knr4 mutants) affects different manner construction. Altogether, 300 responsive genes were kept based on high stringency criteria during data processing. Functional classification these differentially expressed showed...
A reliable acid hydrolysis method for quantitative determination of the proportion β-glucan, mannan and chitin in Saccharomyces cerevisiae cell wall is reported together with a simple extraction procedure to quantify within standard error less than 2% per gram dry mass. This an optimized version Saeman's based on sulfuric complex polysaccharides. It resulted almost complete release glucose, mannose glucosamine residues from After removal sulfate ions by precipitation barium hydroxide,...
Summary Caffeine is a natural purine analogue that elicits pleiotropic effects leading ultimately to cell's death by largely uncharacterized mechanism. Previous works have shown this drug induces rapid phosphorylation of the Mpk1p, final mitogen‐activated protein (MAP) kinase Pkc1p‐mediated cell integrity pathway. In work, we showed did not necessitate main wall sensors Wsc1p and Mid2p, but was abolished upon deletion ROM2 encoding GDP/GTP exchange factor Rho1p. We also caffeine‐induced...
The genetic control of common traits is rarely deterministic, with many genes contributing only to the chance developing a given phenotype. This incomplete penetrance poorly understood and usually attributed interactions between or environmental conditions. Because such as cancer can emerge from rare events happening in one very few cells, we speculate an alternative complementary possibility where some genotypes could facilitate these by increasing stochastic cell-to-cell variations (or...
In a previous paper we reported that β-d-glucans isolated from Saccharomyces cerevisiae could adsorb zearalenone, reduce its bioavailability in the digestive tract, and protect animals against adverse effects. We have now investigated, vitro, kinetics of interaction between other mycotoxins several sources at three pH values found along tract (3.0, 6.0, 8.0). Acid neutral conditions gave highest affinity rates for aflatoxins B1 > deoxynivalenol ochratoxin A involved both (1 → 3)-β-d-glucans...
Abstract We have isolated a snf1/ccr1 mutant of Saccharomyces cerevisiae which loses viability upon starvation and fails to accumulate glycogen in response abrupt depletion phosphate or glucose. A snf1 null is sensitive heat stress during growth rich medium. The phenotypes the mutants are those commonly associated with an overactivation adenylate cyclase pathway. Mutations RAS2 decrease level cAMP cell moderate phenotype. In contrast, mutation (RAS2val19) increases regulatory subunit (BCY1)...
When glucose was added to a suspension of Saccharomyces cerevisiae in stationary phase, it caused transient increase the concentration cyclic AMP and more persistent hexose 6-phosphate fructose 2,6-bisphosphate. These effects on 2,6-bisphosphate but not that were greatly decreased presence 0.15 mM acridine orange or when temperature-sensitive mutant deficient adenylate cyclase used at restrictive temperature. Incubation cells dinitrophenol absence increased both 2,6-bisphosphate, with...
2-Phenylethanol is an aromatic compound commonly used in the food, cosmetic, and pharmaceutical industries. Due to increasing demand for natural products by consumers, production of this flavor microbial fermentation gaining interest, as a sustainable alternative chemical synthesis or expensive plant extraction, both processes relying on use fossil resources. However, drawback process high toxicity 2-phenylethanol producing microorganism. The aim study was obtain 2-phenylethanol-resistant...
ABSTRACT The β-galactosidase from the Antarctic gram-negative bacterium Pseudoalteromonas haloplanktis TAE 79 was purified to homogeneity. nucleotide sequence and NH 2 -terminal amino acid of enzyme indicate that subunit is composed 1,038 acids with a calculated M r 118,068. This shares structural properties Escherichia coli (comparable mass, 51% identity, conservation residues involved in catalysis, similar optimal pH value, requirement for divalent metal ions) but characterized by higher...
Cell walls of yeasts and bacteria are able to complex with mycotoxins limit their bioavailability in the digestive tract when these given as feed additives animals. To identify component(s) yeast cell wall chemical interaction(s) involved formation zearalenone, four strains Saccharomyces cerevisiae differing glucan mannan content were tested. Laboratory wt292, fks1, mnn9 compared industrial S. strain sc1026. The complex-forming capacity was determined vitro by modelling plots amount toxin...
The dynamic responses of reserve carbohydrates with respect to shortage either carbon or nitrogen source was studied obtain a sound basis for further investigations devoted the characterization mechanisms by which yeast Saccharomyces cerevisiae can cope nutrient limitation during growth. This study carried out in well-controlled bioreactors allow accurate monitoring growth and frequent sampling without disturbing culture. Under glucose limitation, genes involved glycogen trehalose...
Carbon isotope distribution of [13C]citrinin from Monascus ruber incubated with [13C]acetate revealed that the biosynthesis toxin originated a tetraketide, instead pentaketide as has been shown for Penicillium and Aspergillus species. The production polyketide red pigments citrinin by M. may therefore be regulated at level tetraketide branch point.
We report here that the open reading frame YKL248, previously identified during systematic sequencing of yeast chromosome XI [Purnelle B., Skala, J., Van Dijck, L. & Goffeau, A. (1992) Yeast 8, 977-986] encodes UDP-glucose pyrophosphorylase (UGPase), enzyme which catalyses reversible formation UDP-Glc from glucose 1-phosphate and UTP. Proof for this function come sequence alignment YKL248 product with UGPase other species, complementation studies an Escherichia coli galU mutant deficient in...