Search results for "bacteri"

Effect of mismatch repair on the mutation rate of bacteriophage ϕX174

2015

Viral mutation rates vary widely in nature, yet the mechanistic and evolutionary determinants of this variability remain unclear. Small DNA viruses mutate orders of magnitude faster than their hosts despite using host-encoded polymerases for replication, which suggests these viruses may avoid post-replicative repair. Supporting this, the genome of bacteriophage ϕX174 is completely devoid of GATC sequence motifs, which are required for methyl-directed mismatch repair in Escherichia coli . Here, we show that restoration of the randomly expected number of GATC sites leads to an eightfold reduction in the rate of spontaneous mutation of the phage, without severely impairing its replicative capa…

Variation in RNA virus mutation rates across host cells.

2014

It is well established that RNA viruses exhibit higher rates of spontaneous mutation than DNA viruses and microorganisms. However, their mutation rates vary amply, from 10−6 to 10−4 substitutions per nucleotide per round of copying (s/n/r) and the causes of this variability remain poorly understood. In addition to differences in intrinsic fidelity or error correction capability, viral mutation rates may be dependent on host factors. Here, we assessed the effect of the cellular environment on the rate of spontaneous mutation of the vesicular stomatitis virus (VSV), which has a broad host range and cell tropism. Luria-Delbrück fluctuation tests and sequencing showed that VSV mutated similarly…

A selective medium for the isolation of malolactic mutants of Leuconostoc oenos

1994

We have developed a selective medium for the isolation of Leuconostoc oenos mutants defective in malolactic fermentation. Forty per cent of colonies isolated directly on selective plates after UV mutagenesis had lost their ability to degrade malate. None of the tested mutants showed any detectable malolactic activity and all lacked a protein band corresponding in size to that of the malolactic enzyme. The availability of such mutants provides a valuable tool both for physiological and genetic research on malolactic fermentation.

Genomic Changes in Bacteria: From Free-Living to Endosymbiotic Life

2007

Symbiosis is the association between two or more distinct organisms during at least one part of their lifecycle. Although this term is sometimes used in a narrower sense, it includes for most authors a set of different situations such as mutualism, parasitism and commensalism. Mutualism is defined as an association in which both partners derive benefit from living together. Parasitism is an association in which one of the partners benefits, while the other is harmed. Finally, commensalism is an association in which one of the two members benefits while the other is neither harmed nor obtains an advantage. In most cases, the association is established between a pluricellular eukaryote and a …

Evolution of lactic acid bacterial populations during lysine fortification of sourdough breads by addition of pistachio powder

2019

Food fortification is a current practise to increase the bioavailability of certain nutrients. In this study, 5% (w/w) pistachio powder was added to tender wheat flour or durum wheat semolina to evaluate its contribution to augment the amount of lysine in bread. Bread production was carried out by sourdough technology using a selected 3-species lactic acid bacterial (LAB) starter culture (Lactobacillus sanfranciscensis PON100336, Leuconostoc citreum PON10079 and Weissella cibaria PON10030). In order to determine the influence of pistachio powder on the evolution of LAB, sourdough bread productions were compared with control trials obtained from flour or semolina and evaluated for the develo…

Die Lepra in Riga, ihre Ausbreitung und Bekämpfung: Vortrag, gehalten am 22. April 1911 in der Gesellschaft für kommunale Sozialpolitik in Riga

1911

"Als Manuskript gedruckt für die Mitglieder der Gesellschaft für kommunale Sozialpolitik in Riga."

Infección pulmonar por Mycobacterium kansasii y carcinoma broncopulmonar sincrónico

2002

Aunque la asociación de tuberculosis pulmonar y carcinoma de pulmón es bien conocida en la literatura, resulta excepcional la presentación sincrónica de la infección pulmonar por micobacterias atípicas y el carcinoma broncopulmonar. Por ello, presentamos el caso de un varón de 41 años, fumador, con antecedentes de tuberculosis pulmonar en la adolescencia y hepatopatía crónica por virus B y C, que acudió a nuestra consulta externa por presentar febrícula, disfonía y pérdida de 4 kg de peso de un mes de evolución. La TC de tórax reveló una masa apical izquierda con extensión a la pared y adenopatías mediastínicas, así como un infiltrado pulmonar en LSI. La biopsia de una adenopatía supraclavi…

Spatiotemporal mapping of the leprosy granuloma landscape

2022

Lepromatous leprosy : a review and case report

2006

Podeu consultar la versió en castellà a http://hdl.handle.net/2445/117327

Inside a Shell—Organometallic Catalysis Inside Encapsulin Nanoreactors

2021

Abstract Compartmentalization of chemical reactions inside cells are a fundamental requirement for life. Encapsulins are self‐assembling protein‐based nanocompartments from the prokaryotic repertoire that present a highly attractive platform for intracellular compartmentalization of chemical reactions by design. Using single‐molecule Förster resonance energy transfer and 3D‐MINFLUX analysis, we analyze fluorescently labeled encapsulins on a single‐molecule basis. Furthermore, by equipping these capsules with a synthetic ruthenium catalyst via covalent attachment to a non‐native host protein, we are able to perform in vitro catalysis and go on to show that engineered encapsulins can be used …