Search results for "bacteri"
showing 10 items of 5466 documents
Wpływ punktowych źródeł zanieczyszczeń na jakość wód dolnego biegu Nysy Kłodzkiej
2000
Identification of a ligand on the Wip1 bacteriophage highly specific for a receptor on B. anthracis.
2013
Tectiviridae is a family of tailless bacteriophages with Gram-negative and Gram-positive hosts. The family model PRD1 and its close relatives all infect a broad range of enterobacteria by recognizing a plasmid-encoded conjugal transfer complex as a receptor. In contrast, tectiviruses with Gram-positive hosts are highly specific to only a few hosts within the same bacterial species. The cellular determinants that account for the observed specificity remain unknown. Here we present the genome sequence of Wip1, a tectivirus that infects the pathogen Bacillus anthracis. The Wip1 genome is related to other tectiviruses with Gram-positive hosts, notably, AP50, but displays some interesting differ…
Bakteriofāgu terapijas iespējas
2016
Pārmērīga antibakteriālu līdzekļu lietošana veicina epidēmijas mēroga bakteriālās rezistences pieaugumu attīstītajās un attīstības valstīs. Bakteriālās rezistences pieaugums atdzīvina interesi par alternatīvām antibakteriālām terapijām. Viena no tām iesaista bakteriofāgus – vīrusus, kuriem piemīt spējas inficēt un vairoties baktēriju saimniekšūnās veicinot to lizēšanu. Ir plaši dokumentēta fāgu veikta vairāku rezistentu baktēriju izskaušana, tomēr nav skaidrs, caur kādiem mehānismiem tā tiek panākta. Tas apgrūtina regulējošo iestāžu atļauju izsniegšanu, lai ieviestu bakteriofāgu terapiju klīniskajā praksē. Bakalaura darba mērķis bija noskaidrot veselības aprūpes speciālistu (ārstu) viedokli…
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…
Functional and Taxonomic Diversity in Maritime Antarctic Lakes
2015
El área conocida como Península Byers (Isla Livingston, Antártida) se caracteriza por ser una de las zonas libres de hielo más grandes de la Antártida marítima, mostrando un importante número de cuerpos de agua libres de hielo durante el verano austral. Estas características y su estatus como zona Antártica de especial protección (ASPA) han convertido a la Península Byers en un sitio de referencia para estudios limnológicos en la Antártida marítima. La presente tesis trata sobre el estudio de los lagos ubicados en la Península Byers, centrándose en el lago Limnopolar, utilizado como modelo para estudios limnológicos durante las últimas décadas. El estudio de la heterogeneidad ambiental en l…
Retinal Vibrations in Bacteriorhodopsin are Mechanically Harmonic but Electrically Anharmonic: Evidence From Overtone and Combination Bands
2021
Fundamental vibrations of the chromophore in the membrane protein bacteriorhodopsin (BR), a protonated Schiff base retinal, have been studied for decades, both by resonance Raman and by infrared (IR) difference spectroscopy. Such studies started comparing vibrational changes between the initial BR state (all-trans retinal) and the K intermediate (13-cis retinal), being later extended to the rest of intermediates. They contributed to our understanding of the proton-pumping mechanism of BR by exploiting the sensitivity of fundamental vibrational transitions of the retinal to its conformation. Here, we report on new bands in the 2,500 to 1,800 cm−1 region of the K-BR difference FT-IR spectrum.…
Tempo and mode of early gene loss in endosymbiotic bacteria from insects
2006
Abstract Background Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia floridanus) to test if gene loss could be driven by the selective importance of genes. We used a parsimony method to reconstruct a minimal ancestral genome of insect endosymbionts and quantified gene loss along the branches of the phylogenetic tree. To evaluate the selective or functional importance of genes, we used a parameter that meas…
Characterization of the ligands for the human umami taste receptor
2017
National audience; Among our basics senses, taste and our gustatory system allow us to perceive and recognize essential chemical nutrients present in food. Human can detect and discriminate five basics taste (sweet, bitter, sour, salty and umami) and recent studies proposed a sixth taste for fat. The umami taste is described as a « savory » sensation elicited mainly by L-amino acids and is thought to serve as an indicator of protein rich foods and promote feeding.The umami taste receptor is a heterodimeric receptor composed of the T1R1 and T1R3 subunits. These subunits belong to the family class C G protein-coupled receptors (GPCRs) and are constituted by a large N-terminal domain (NTD) lin…
Diversité des communautés microbiennes telluriques à l'échelle du territoire national
2009
Communication orale - résumé Session 5 : sols, biodiversité, écologie fontionnelleCommunication orale - résumé Session 5 : sols, biodiversité, écologie fontionnelle; absent