Search results for "Coccus"
showing 10 items of 1002 documents
Discovering lactic acid bacteria by genomics
2002
International audience; This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, environmental habitat, and its role in fermentation, bioprocessing, or probiotics. For those projects where genome sequence data were available by March 2002, summaries include a listing of key statistics and interesting genomic features. These efforts will revolutionize our molecular view of Gram-positive bacteria, as up to 15 genomes from the low GC content lactic acid bacteria are expected to be available in the pu…
Engineering a Saccharomyces cerevisiae Wine Yeast That Exhibits Reduced Ethanol Production during Fermentation under Controlled Microoxygenation Cond…
2006
ABSTRACTWe recently showed that expressing an H2O-NADH oxidase inSaccharomyces cerevisiaedrastically reduces the intracellular NADH concentration and substantially alters the distribution of metabolic fluxes in the cell. Although the engineered strain produces a reduced amount of ethanol, a high level of acetaldehyde accumulates early in the process (1 g/liter), impairing growth and fermentation performance. To overcome these undesirable effects, we carried out a comprehensive analysis of the impact of oxygen on the metabolic network of the same NADH oxidase-expressing strain. While reducing the oxygen transfer rate led to a gradual recovery of the growth and fermentation performance, its i…
Cyclopropane Fatty Acid Synthase from Oenococcus oeni: Expression in Lactococcus lactis subsp. Cremoris and Biochemical Characterization
2015
Bacterial cyclopropane fatty acid synthases (CFA synthases) catalyze the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to the double bond of a lipid chain, thereby forming a cyclopropane ring. CFAs contribute to resistance to acidity, dryness, and osmotic imbalance in many bacteria. This work describes the first biochemical characterization of a lactic acid bacterium CFA synthase. We have overexpressed Oenococcus oeni CFA synthase in E. coli in order to purify the enzyme. The optimum cyclopropanation activity was obtained at pH 5.6 and 35.8 °C. The high K(m) (AdoMet) value obtained (2.26 mM) demonstrates the low affinity of O. oeni enzyme toward the L. lactis subsp. cremo…
Echinococcus multilocularis in urban and rural foxes of the Czech Republic
2004
International audience
Echinococcus multilocularis in France: First results
2003
International audience
Les relations paysage-hôtes dans les processus épidémiologiques du parasite Echinococcus multilocularis
2005
National audience
Functional response of species to multiscale landscape structure in a vector-borne disease
2007
International audience; The functional response of species to landscape is a recurring issue in landscape ecology. The scale levels favourable to the parasite responsible for a vector-borne disease, alveolar echinococcosis, have been explored in the Doubs department in eastern France. The method consists in maximizing landscape composition's heterogeneity in the environment of infected and non-infected georeferenced samples at various scales. The aim is to identify scale levels at which the positive samples' landscapes are the most specific and differ the most from the landscape in the environment of all samples. Three scales were identified and the distance to the positive samples' composi…
Environmental risk factors for transmission and representing Echinococcus multilocularis gradients in space and time: fox data, models and scale depe…
2004
International audience
Novel liquid starter cultures for malolactic fermentation in wine
2014
La fermentación maloláctica es fundamental para la calidad del vino, especialmente en el vino tinto. Se trata de la transformación del ácido L-málico procedente de las uvas, de un gusto fuerte y áspero, en ácido L-láctico, de gusto más agradable, liberándose además CO2. Esta fermentación puede ser una poderosa herramienta en la elaboración del vino, no solo por reducir su acidez, sino también por influir positivamente en el aroma y perfil sensorial del vino. Esta fermentación es llevada a cabo por bacterias lácticas, pero no siempre se realiza en el momento oportuno ni en las condiciones óptimas, ya que son muchos los factores que influyen en su crecimiento y desarrollo. Una de las estrateg…
Le choix de descripteurs paysagers en tant qu'indicateurs d'un risque épidémiologique
2005
National audience; Echinococcus multilocularis (Em) est un parasite responsable chez l'homme d'une maladie grave : l'échinococcose alvéolaire. La contamination humaine peut se produire par ingestion accidentelle d'œufs du parasite. Un programme européen d'épidémiosurveillance, EchinoRisk, est actuellement en cours. En France, ce programme, mené conjointement par l'ERZ (Entente interdépartementale de lutte contre la rage et autres zoonoses) et l'AFSSA (Agence française de sécurité sanitaire des aliments), a permis jusqu'à présent de collecter 5 820 échantillons localisés de fèces de renards. À ce jour, 2 305 échantillons ont été analysés parmi lesquels 62 ont révélé la présence du parasite. …