Search results for " microorganism"
showing 10 items of 81 documents
Changes in gene expression during adaptation of Listeria monocytogenes to the soil environment
2011
project SEST 009; International audience; Listeria monocytogenes is a ubiquitous opportunistic pathogen responsible for listeriosis. In order to study the processes underlying its ability to adapt to the soil environment, whole-genome arrays were used to analyse transcriptome modifications 15 minutes, 30 minutes and 18 h after inoculation of L. monocytogenes EGD-e in soil extracts. Growth was observed within the first day of incubation and large numbers were still detected in soil extract and soil microcosms one year after the start of the experiment. Major transcriptional reprofiling was observed. Nutrient acquisition mechanisms (phosphoenolpyruvate-dependent phosphotransferase systems and…
Caracterización de los componentes genéticos y ambientales implicados en el envejecimiento de las levaduras vínicas
2012
La mayor parte de la fermentación vínica discurre cuando las células de la levadura Saccharomyces cerevisiae han dejado de dividirse. Así pues, la viabilidad en fase estacionaria, llamada longevidad cronológica (LC), es esencial para que la vinificación se lleve a buen término. En este trabajo de tesis doctoral, se han caracterizado diversos componentes ambientales y genéticos que influyen en la longevidad cronológica de las levaduras vínicas. En cuanto a los componentes ambientales, el incremento de la acidez y la temperatura del medio promueven el envejecimiento. Los polifenoles resveratrol y quercetina y los compuestos de dos carbonos que se producen durante la fermentación, afectan de m…
Association of burning mouth syndrome with xerostomia and medicines
2005
Objetivo: Identificar factores de riesgo para el síndrome de boca ardiente (SBA) a través de estudio de casos y controles. Material y métodos: Se realizó análisis cuantitativo del flujo salival total en reposo y estimulado; se registraron la xerostomía subjetiva, el consumo de medicamentos y los estados psicológicos de ansiedad y depresión en 40 pacientes con SBA y 40 controles. Resultados: El análisis ANOVA mostró diferencias significativas en las medias del número de medicamentos/día, número de medicamentos xerostomizantes/día, xerostomía subjetiva, ansiedad y depresión, entre los grupos estudiados. No se observaron diferencias significativas en las tasas de flujo salival en reposo y esti…
Optimizing Nanopore-based microbiome sequencing for characterizing biotechnologically-relevant ecosystems
2022
La secuenciación de siguiente generación (NGS) ha cambiado completamente la manera en la que estudiamos el mundo microbiano. A lo largo de los últimos años, las plataformas Illumina han sido las más usadas para secuenciar ADN. No obstante, la secuenciación por nanoporos, un nuevo método impulsado por Oxford Nanopore Technologies (ONT), está incrementando gradualmente su popularidad dadas sus múltiples ventajas sobre las plataformas NGS. Estas ventajas incluyen la portabilidad y la capacidad para generar secuencias largas en tiempo real. A pesar de estos avances, la adopción de la secuenciación ONT se ha visto limitada por la elevada tasa de error asociada a esta tecnología en comparación co…
Genomic epidemiology: from transmission to the evolution of pathogenic microorganisms
2022
La epidemiología genómica ha revolucionado el mundo microbiano. Sus aplicaciones permiten conocer y comprender mejor el comportamiento, la transmisión y la evolución de los microorganismos. A pesar de su gran y reconocido potencial, su uso aún es limitado, especialmente en regiones en desarrollo. El principal objetivo de esta tesis fue estudiar y analizar los genomas completos de tres microorganismos patógenos y zoonóticos para comprender mejor su epidemiología, potencial patogénico y evolución. En el primer capítulo caracterizamos a nivel genómico a Salmonella enterica aislada de alimentos, fincas y muestras clínicas en Ecuador. Además, presentamos evidencia de la presencia de factores de …
Scientific Opinion addressing the state of the science on risk assessment of plant protection products for in‐soil organisms
2017
Abstract Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science behind the risk assessment of plant protection products for in‐soil organisms. The current risk assessment scheme is reviewed, taking into account new regulatory frameworks and scientific developments. Proposals are made for specific protection goals for in‐soil organisms being key drivers for relevant ecosystem services in agricultural landscapes such as nutrient cycling, soil structure, pest control and biodiversity. Considering the time‐scales and biological processes related to the dispersal of the majority of in‐soil organisms compared to terrestrial non…
Refreigerated storage of raw milk for Trentingrana production: microbiological effects
2008
Chemical Ecology of Floral Resources in Conservation Biological Control.
2023
Conservation biological control aims to enhance populations of natural enemies of insect pests in crop habitats, typically by intentional provision of flowering plants as food resources. Ideally, these flowering plants should be inherently attractive to natural enemies to ensure that they are frequently visited. We review the chemical ecology of floral resources in a conservation biological control context, with a focus on insect parasitoids. We highlight the role of floral volatiles as semiochemicals that attract parasitoids to the food resources. The discovery that nectar-inhabiting microbes can be hidden players in mediating parasitoid responses to flowering plants has highlighted the co…
Genome Characterization of natural Saccharomyces hybrids of biotechnological interest
2012
At present, the genus Saccharomyces comprises seven species according to their patterns of breeding. The species boundaries are not clear due to the description of several reticulate events due to introgression and hybridization. In the last decade, new natural hybrids have been described in wine and brewing, such as S. cerevisiae x S. kudriavzevii. Due to new practices in wine and beer production, together with consequences in grape properties due to climatic change, led biotechnological companies to search for new yeast strains. In this context, hybrids have become of importance to biotechnological industries because they show good fermentative performance at low temperatures and produce …
Contribution of Molecular Structure to Self-Assembling and Biological Properties of Bifunctional Lipid-Like 4-(
2019
The design of nanoparticle delivery materials possessing biological activities is an attractive strategy for the development of various therapies. In this study, 11 cationic amphiphilic 4-(N-alkylpyridinium)-1,4-dihydropyridine (1,4-DHP) derivatives differing in alkyl chain length and propargyl moiety/ties number and position were selected for the study of their self-assembling properties, evaluation of their cytotoxicity in vitro and toxicity on microorganisms, and the characterisation of their interaction with phospholipids. These lipid-like 1,4-DHPs have been earlier proposed as promising nanocarriers for DNA delivery. We have revealed that the mean diameter of freshly prepared nanoparti…