Search results for "cytométrie en flux"
showing 8 items of 8 documents
Dissecting the factors controlling seed development in the model legume Medicago truncatula
2012
Legumes are not only indispensible for sustainable agriculture but are also a rich source of protein in food and feed for humans and animals, respectively. However, major proteins stored in legume seeds are poor in sulfur-containing amino acids, and may be accompanied by anti-nutritional factors causing low protein digestibility problems. In this regard, Medicago truncatula serves as a model legume to study legume seed development especially the phase of seed storage protein accumulation. As developing legume seeds are complex structures, a thorough knowledge of the morphogenesis of the seed and the characterization of regulatory mechanisms underlying the embryo development and seed filling…
Evaluation of the toxicity of mussels from 2 sites of the Moroccan Atlantic Coast (Jorf Lasfar and Oualidia) used as bioindicators of contamination :…
2012
Toxic substances generated by various human activities are spilled on different area of the Moroccan coast. Shellfishes can concentrate pollutants and have some adverse effects on human health through the food chain. Despite the strengthening of food safety rules, the involvement of chemical pollution of food on metabolic disorders is not known. To predict the impact of pollutants on the aquatic ecosystem and human health, the development of appropriate biomonitoring tools is required.We quantified heavy metals (Cd, Cr and Pb) in mussels (Mytilus galloprovincialis) from two sites of Moroccan Atlantic coast (industrial site Jorf Lasfar (JL) and touristic site Oualidia (OL)) due to the proxim…
Development of methods for the detection and quantification of spoilage microorganisms in wine : study of growing factors
2016
New practices used to elaborate wine lead to an increase of wine spoilage due to microorganisms. That is why, new technics have to be developed to quantify these microorganisms accurately, quickly and with low costs. The main wine spoilages are due to acetic acid bacteria (AAB) (A. aceti, A. pasteurianus, G. oxydans and Ga. liquefaciens) and Brettanomyces bruxellensis development. AAB transforms ethanol to acetic acid while B. bruxellensis transforms hydroxycinnamic acids to ethyl phenols (EP) (unpleasant odor molecules). In order to detect these wine spoilage microrganisms, flow cytometry coupled to fluorescent in situ hybridization has been assessed. No reproducible results have been deve…
Study of yeast-yeast interactions in fermentative medium
2019
Alcoholic fermentation is the main step for winemaking, mainly performed by the yeast Saccharomyces cerevisiae. But other wine yeasts called non-Saccharomyces may contribute to alcoholic fermentation and improve the wine aroma complexity. The recurrent problem with the use of these non-Saccharomyces yeasts is their trend to die off prematurely during alcoholic fermentation, leading to a lack of their interesting aromatic properties searched in the desired wine. This phenomenon appears to be mainly due to interactions with S. cerevisiae. These interactions are most of the time negatives but remain unclear because of the species and strain specific response. That is why several studies focuse…
Monitoring of mixed culture fermentations
2022
Current and future constraints linked to climate change and evolution of wine consumer demand are prompting the winemaking industry to consider adopting new practices to address the technical challenges resulting from this context. These challenges include the need to maintain a constant alcohol level despite increased sugar contents in the must, and to seek a wider diversity of aromatic profiles, while maintaining acceptable reproducibility.Fermentations with addition of non-Saccharomyces yeasts to the Saccharomyces cerevisiae species traditionally used to conduct alcoholic fermentation seem to be an interesting alternative to achieve these objectives. However, the numerous interactions be…
Etude et caractérisation de l'état " Viable mais Non Cultivable " chez Brettanomyces, une levure d'altération des vins : nouvel outil de détection et…
2011
The viable but not culturable (VBNC) state has been studied in detail in bacteria. It has been suggested that the VBNC state also exists in eukaryote cells, such as wine yeasts, including Brettanomyces in particular. We investigated the VBNC state in this yeast, focusing on the conditions for entry and exit, and the morphological and metabolic modifications associated with this state. We added sulfite (0.8 mg.L-1 molecular SO2) to induce the VBNC state. Increasing the pH of the medium inactivated the sulfite, allowing the cells to exit from the VBNC state and to become culturable again. In these conditions, we found that Brettanomyces VBNC cells were smaller than culturable cells, and that …
Recherche de critères phénotypiques et moléculaires discriminants des différentes espèces et sous-espèces du genre Pisum
2014
The Pisum genus presents a large genetic diversity, that makers difficult its taxonomic classification. The Center for Grain Legumes Genetic Resources holds 1800 pea accessions. Some of them are lacking passport data. Previous genotyping studies have identified SNP markers specific to wild Pisum pools. The main aim of my work was to conceive simple criteria in order to classify the unknown genotypes. Towards this goal, plants have been observed at the phenotypic level and their DNA were extracted for their characterisation using discriminating SNP markers. Furthermore, candidate genes of domestication were sequenced. Our results clearly showed distinctive traits between the P. sativum and P…
Influence de l'auxine sur le developpement in vitro de la graine de Medicago truncatula, genotype sauvage et transformants
2012
Rapport de stage Master 1 Sciences, Technologies, Vie, Terre et Santé. Spécialité Biologie Cellulaire et Physiologie BAP GEAPSI CT2