Search results for "bacteri"
showing 10 items of 5466 documents
Bioaccumulation of selenium-by fruit origin lactic acid bacteria in tropical fermented fruit juices
2021
Abstract Adequate fruit consumption helps to prevent several chronic age-related diseases. Selenium (Se) is an elemental micronutrient with antioxidant capacity. In general, fruits and Se ingest by humans are below the recommended daily intake value. Fresh fruits are highly susceptible to deterioration during storage. Fermentation can improve the storage period, sensory profile, and bioactive compound content of foods; moreover, some lactic acid bacteria can accumulate organic Se intracellularly. In this work, microbial growth and Se accumulation by Levilactobacillus brevis CRL2051 and Fructobacillus tropaeoli CRL2034 in tropical fruit juices were evaluated. The strains could grow 1–2 log c…
The Effect of Pesticides on the Tomato Bacterial Speck Disease Pathogen Pseudomonas Syringae pv. Tomato
2020
A significant part of the used pesticides does not reach the target organisms and, while remaining in the agrophytocenosis, influences all living organisms in it. Having a toxic and often mutagenic effect, pesticides induce morphological and physiological changes in the cells of microorganisms and are the cause of phenotypic heterogeneity of their populations. However, the effect of pesticides on phytopathogenic bacteria as non-target microorganisms remains out of the field of view for most researchers. However, the use of pesticides can lead to expansion of the diversity of existing phytopathogens and, as a consequence, complications of identification of the pathogens, loss of resistance b…
Local response of bacterial densities and enzyme activities to elevated atmospheric CO2 and different N supply in the rhizosphere of Phaseolus vulgar…
2008
Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; Altered flux of labile C from plant roots into soil is thought to influence growth and maintenance of microbial communities under elevated atmospheric CO2 concentrations. We studied the abundance and function of the soil microbial community at two levels of spatial resolution to assess the response of microorganisms in the rhizosphere of the whole root system and of apical root zones of Phaseolus vulgaris L. to elevated CO2 and high or low N supply. At the coarser resolution, microb…
Oxygen as a morphogenic factor in sponges: expression of a tyrosinase gene in the sponge Suberites domuncula
2004
Sponges live in a symbiotic relationship with microorganisms, especially bacteria. Here we show, using the demosponge Suberites domuncula as a model, that the sponge expresses the enzyme tyrosinase which synthesizes diphenols from monophenolic compounds. It is assumed that these products serve as carbon source for symbiotic bacteria to grow.
Degradation of vanillic acid and production of guaiacol by microorganisms isolated from cork samples
2003
The presence of guaiacol in cork stoppers is responsible for some cases of cork taint causing unpleasant alterations to wine. We have performed a characterization of the cork-associated microbiota by isolating 55 different microorganisms: eight yeast, 14 filamentous fungi or molds, 13 actinomycetes and 20 non-filamentous bacteria. A screening for degradation of vanillic acid and guaiacol production showed that none of the filamentous fungi could achieve any of these processes. By contrast, five of the eight yeast strains isolated were able to degrade vanillic acid, although it was not converted to guaiacol. Guaiacol production was only detected in four bacterial strains: one isolate of Baci…
Increase of sulfite tolerance in Oenococcus oeni by means of acidic adaptation
1998
International audience; Sulfite is an antimicrobial agent used at the beginning of winemaking to avoid development of undesirable microorganisms. However, Oenococcus oeni, which is mainly responsible for the malolactic fermentation, has to grow in wine and therefore has to be resistant to sulfite. This study showed that acid-adapted cells of O. oeni survived better than non-adapted cells in the presence of a high sulfite concentration (30 mg l-1). Addition of a sub-lethal concentration of sulfite (15 mg l31) during the adaptation step in acidic medium increases the sulfite tolerance. Moreover, sulfite appeared to be able to induce a heat shocklike response. Our results suggest that pH homeo…
Documento de consenso sobre el tratamiento antimicrobiano de las infecciones bacterianas odontogénicas
2005
Las infecciones de la cavidad bucal son un problema de salud pública frecuente y motivo constante de prescripción antibiótica; el 10% de los antibióticos se emplean para tratar este problema. Sin embargo, hasta la fecha son pocos los estudios realizados para determinar su incidencia. Asímismo, su relación con ciertas enfermedades sistémicas (cardiacas, endocrinas, etc...) confiere a estas patologías una importancia vital. A pesar de la reconocida frecuencia e importancia de las infecciones odontogénicas, llama la atención la actual dispersión de criterio en varios aspectos referentes a su clasificación, terminología y recomendaciones terapéuticas. El objetivo principal de este documento, re…
Phylogenomic evidence for the presence of a flagellum and cbb(3) oxidase in the free-living mitochondrial ancestor.
2011
The initiation of the intracellular symbiosis that would give rise to mitochondria and eukaryotes was a major event in the history of life on earth. Hypotheses to explain eukaryogenesis fall into two broad and competing categories: those proposing that the host was a phagocytotic proto-eukaryote that preyed upon the free-living mitochondrial ancestor (hereafter FMA), and those proposing that the host was an archaebacterium that engaged in syntrophy with the FMA. Of key importance to these hypotheses are whether the FMA was motile or nonmotile, and the atmospheric conditions under which the FMA thrived. Reconstructions of the FMA based on genome content of Rickettsiales representatives-gener…
Effect of alkaline ph on sealing ability of white mineral trioxide aggregate
2011
Objectives: The aim of this study was to evaluate microleakage of white mineral trioxide aggregate (WMTA) after its exposure to a range of alkaline environments during hydration. Study Design: Seventy single-rooted teeth were divided into 4 experimental and 2 control groups. All the teeth were instrumented, and their apices were resected. Root-end cavities were filled with WMTA in the experimental groups. In the control groups, root-end cavities were not filled. Root-end fillings were exposed to alkaline environments with pH values of 7.4, 8.4, 9.4, or 10.4 for 3 days. Microleakage was evaluated by bovine serum albumin. Evaluations were carried out at 24-hour intervals for 80 days. Data wer…
Marine biominerals: perspectives and challenges for polymetallic nodules and crusts.
2009
Deep sea minerals in polymetallic nodules, crusts and hydrothermal vents are not only formed by mineralization but also by biologically driven processes involving microorganisms (biomineralization). Within the nodules, free-living and biofilm-forming bacteria provide the matrix for manganese deposition, and in cobalt-rich crusts, coccolithophores represent the dominant organisms that act as bio-seeds for an initial manganese deposition. These (bio)minerals are economically important: manganese is an important alloying component and cobalt forms part of special steels in addition to being used, along with other rare metals, in plasma screens, hard-disk magnets and hybrid car motors. Recent p…