Search results for "Microbio"
showing 10 items of 8741 documents
Stochastic model for a biological complex system: analysis of the bacterial growth in food products
2012
The Physics of Complex Systems has recently taken a more and more important role in the description of natural systems because of the interactions, both deterministic and noisy, between such systems and the environment. In particular the noise plays a relevant role in biological systems, whose dynamics is strongly influenced by environmental variables subject to random fluctuations. In this work a stochastic model is exploited to reproduce the growth of bacteria in food of animal origin. Specifically the dynamics of a bacterial species, Listeria monocytogenes, is analyzed in the presence of lactic acid bacteria (LAB) during the period of the fermentation of meat products. The model, based o…
Dextranos de bacterias lácticas aisladas de productos cárnicos: caracterización y aplicaciones
2015
153 p.-46 fig.-9 tab.-2 anexos
Cooperation between Different CRISPR-Cas Types Enables Adaptation in an RNA-Targeting System
2021
CRISPR-Cas systems are immune systems that protect bacteria and archaea against their viruses, bacteriophages. Immunity is achieved through the acquisition of short DNA fragments from the viral invader’s genome.
Silent rain: does the atmosphere-mediated connectivity between microbiomes influence bacterial evolutionary rates?
2020
ABSTRACT Air carries a vast number of bacteria and viruses over great distances all the time. This leads to continuous introduction of foreign genetic material to local, established microbial communities. In this perspective, I ask whether this silent rain may have a slowing effect on the overall evolutionary rates in the microbial biosphere. Arguably, the greater the genetic divergence between gene ‘donors’ and ‘recipients’, the greater the chance that the gene product has a deleterious epistatic interaction with other gene products in its genetic environment. This is due to the long-term absence of check for mutual compatibility. As such, if an organism is extensively different from other…
EMbaRC designing training and e-learning materials for biological resource centres
2012
International audience; The European Consortium of Microbial Resource Centres (EMbaRC, www.embarc.eu) is a research infrastructure project gathering together the major microbial Biological Resource Centres (BRCs) in Europe. These cultures collections have a long and respected tradition in training people that are involved in microbial taxonomy, preservation and management. Advanced and bespoke courses on related topics add high value to the European educational community and create a knowledge-based training network. Under the framework of EMbaRC, the training programmes offered by the consortium were surveyed and schemes were proposed to establish an educational community to create a knowl…
Les souches d’Escherichia coli résistantes aux antibiotiques
2017
Parmi les bactéries multi-résistantes, les entérobactéries productrices de β-lactamase à spectre élargi (BLSE) occupent une place croissante. Parmi celles-ci, c’est Escherichia coli (entérobactérie commensale du tube digestif de l’homme et de l’animal) qui est l’espèce la plus concernée par cette production enzymatique. Cependant, il existe peu de données sur l’existence de réservoirs environnementaux pour ces souches, leur capacité à survivre dans l’environnement et en particulier dans les eaux douces et dans les sols. Le projet "CIREC" visait donc à étudier la prévalence et la caractérisation des souches d’E.coli productrices de BLSE de type CTX-M dans les eaux usées et les boues issues d…
Biodegradazione di miscele di gasolio in suoli contaminati
2008
Il biorisanamento mediante l’utilizzo di microrganismi ha un ruolo fondamentale nelle pratiche di trasformazione di molecole potenzialmente tossiche quali gli idrocarburi, che quotidianamente vengono riversati negli ecosistemi provocando fenomeni di antropizzazione in equilibri naturali particolarmente sensibili. Numerosi ceppi batterici sono abili degradatori e mineralizzatori di sostanze inquinanti xenobiotiche di sintesi e recalcitranti non esistenti in natura, quali i derivati di idrocarburi aromatici e policlorobifenili (PCB). Mediante colture su mezzo minerale Bushnell-Haas agarizzato (BH) in presenza di una miscela di idrocarburi come unica fonte di carbonio sono stati isolati 5 cepp…
Degradazione di pesticidi organofosforici in matrici ambientali
2008
Matrici quali acqua, suolo ed aria sono costantemente soggette a forti pressioni antropiche. I pesticidi pur avendo apportato grandi benefici alle attività agricole influiscono negativamente sugli equilibri degli ecosistemi. Circa 85-90% dei principi attivi applicati in agricoltura non raggiunge gli organismi a cui sono destinati, ma viene disperso nell’ambiente. In tale contesto l’individuazione di microrganismi deputati alla loro degradazione diventa un importante mezzo per la salvaguardia ambientale e della salute umana. Lo scopo del presente lavoro è stato quello di isolare batteri del suolo capaci di degradare composti organofosforici, i quali rivestono una notevole importanza nelle pr…
Consumer Preference Heterogeneity Evaluation in Fruit and Vegetable Purchasing Decisions Using the Best–Worst Approach
2019
This study assesses consumer preferences during fruit and vegetable (FV) sales, considering the sociodemographic variables of individuals together with their choice of point of purchase. A choice experiment was conducted in two metropolitan areas in Northwest Italy. A total of 1170 consumers were interviewed at different FV purchase points (mass retail chains and open-air markets) using a paper questionnaire. The relative importance assigned by consumers to 12 fruit and vegetable product attributes, including both intrinsic and extrinsic quality cues, was assessed by using the best&ndash
Purification and characterization of an intracellular family 3 β-glucosidase from Lactobacillus sanfranciscensis CB1
2005
Lactobacillus sanfranciscensis CB1 uses cellobiose and other β-glucosides (methyl-β-glucoside, arbutin, amygdalin and salicin) as carbon sources. A hexameric ca. 288 kDa β-glucosidase was purified to homogeneity from Lact. sanfranciscensis CB1 by four chromatographic steps. The enzyme was optimally active at pH 7.5 and 40°C. It had a pI of ca. 4.38 and a D55°C value of ca. 27 sec. Almost total inhibition was found with sulfhydryl-modifying agents and divalent cations such as Cu2+, Co2+, Hg2+, Ni2+ and Fe2+ at a concentration of 2 mM. The enzyme was active towards β-(1→4) substrates such as p-nitrophenyl-β-D-glucoside, -D-galactoside and -L-rhamnoside, and cellobiose. The sequencing of four …