Search results for "bactéries"
showing 8 items of 18 documents
Infestation chez le pigeon biset (Columbia livia) en environnement urbain par différentes souches bactériennes pathogènes : prévalence dans la popula…
2014
Rapport de Stage de Master 2 EA MERS CT3; Master; La dissémination des zoonoses est une préoccupation majeure pour les autorités concernées en termes de santé publique. Ces maladies font l’objet de suivi temporel et spatial afin de comprendre les facteurs favorisant leur dissémination. Les oiseaux, de par leur forte capacité de mouvement représentent un groupe taxonomique très étudié dans la dissémination des pathogènes. Le pigeon biset (Columbia liva) est une des espèces les plus présentes dans l’environnement urbain et peut-être porteur de différentes souches bactériennes pathogènes. Cette étude s’est intéressé à estimer l’état sanitaire des pigeons au sein de la ville de Dijon. La recher…
Study of biogenic amines metabolism in wine lactic acid bacteria
2011
Biogenic amines are indesirable compounds found in fermented products like wine. Lactic acid bacteria from wine, including Oenococcus oeni, the main actor of malolactic fermentation, are able to produce these molecules from nitrogenous precursors. In order to limited biogenic amines accumulation, it is necessary to understand the role of this production by strains responsible for the synthesis of these metabolites in food. That is why the European BiamFood project was put in place. Along my thesis, molecular tools were developed in order to mutate O. oeni genes (encoding decarboxylases), and to express genes of interest. Genetic clusters hdc from L. higardii and odc from O. oeni, responsibl…
Selection of probiotic strains and improving the survival and functionality of an academic strain, Bifidobacterium bifidum, by changing the redox pot…
2012
The aim of this work was to select rationally a probiotic strain by setting up a screening method as well as study and understand the impact of the redox potential (Eh) and gas bubbling on the survival of Bifidobacterium bifidum in a fermented dairy product. In a first time, we have developed selection techniques of probiotic bacteria on the criteria of viability / vitality (flow cytometry analysis) and on the criteria of functionality (antioxidant). We were able to select strains of industrial interest as well as an academic strain, Bifidobacterium bifidum.Secondly, we have studied effect of modifying redox potential by gas bubbling on the survival of B. bifidum in a fermented dairy produc…
Screening of lactic acid bacteria for their use as aromatic starters during fermentation of vegetables
2020
Lactic acid bacteria (LAB) have good growth capacities on various food matrices and produce very diverse enzymatic activities which are notably capable of positively modifying the organoleptic properties of fermented foods. Therefore, the selection of the LAB starters possessing good metabolic abilities and interesting enzymatic activities towards the plant matrix could improve the aroma profiles of fermented foods. The main objective of this study was to enhance the aroma profiles of fermented tomatoes by using the biotechnological pathway. To achieve this, firstly, 200 LAB isolated from Cambodian and Vietnamese fermented foods were screened for their β-glucosidase activity and duplicate i…
Influence de différentes pratiques agricoles sur la qualité et la santé des sols : étude de cas sur des vergers slovènes irrigués ou en agriculture b…
2011
Underestimation of soil properties and poor understanding of soil conditions can have many negative consequences, which results in quality or quantity of yield, soil degradation or even environmental pollution. According to importance of agricultural practices, our study focused on their impact on soil quality and health. The research took place from November 2003 to October 2007 in apple orchards in north-eastern Slovenia where two frequent agricultural practices were investigated: (i) drip irrigation on Calcaric Cambisol and its effects on structural stability and microbial biomass at Gačnik experimental station and (ii) combination of organic fertiliser (Campo guano) and liming in organi…
La biodiversité de la microflore du sol prévient l’implantation de pathogènes alimentaires dans les sols agricoles
2015
Pôle EA MERS; National audience; La présence dans les agroécosystèmes de bactéries pathogènes pouvant être transmises à l’homme représente un risque sanitaire pour l’ensemble de la filière de production des aliments. Le sol est en effet une zone de transfert potentiel de ces agents pathogènes vers les matières premières agricoles, puis vers les produits agroalimentaires, la plupart du temps dans des produits animaux, mais aussi via des produits végétaux également.
Services provided by soil microorganisms to improve plant phosphate nutrition
2022
Since the first Green Revolution, agricultural practices have been based on the massive use of synthetic fertilisers and plant protection products. Since then, global consumption of phosphate fertilisers has more than tripled, reaching 47 million tonnes in 2019. Current projections estimate that phosphate rock stocks (natural phosphorus resources for fertiliser production) could be depleted within the next century, leading us to change our agricultural practices. In soils, P is mainly present in complexed forms that are not easily accessible to plants. To reduce the use of phosphate fertilisers, it is necessary to make this complexed phosphate accessible to plants. This can be done by benef…
«Comment mieux faire fonctionner le sol ?» : le rôle des champignons, des mycorhizes et des bactéries du sol et le lien avec les pratiques agricoles
2017
SPEIPMUB; «Comment mieux faire fonctionner le sol ?» : le rôle des champignons, des mycorhizes et des bactéries du sol et le lien avec les pratiques agricoles. Journée Innovation Agronomique VIVESCIA " les couverts en interculture pour developper le sol"