Search results for "bacteri"

Methods for studying root colonization by introduced beneficial bacteria

2003

e-Book; Some free-living rhizobacteria are considered as potential biocontrol and plant growth-promoting agents. Successful application of beneficial bacteria as microbial inoculants requires their presence and activity at the appropriate level, but even more, at the right time and place. Various markers are described in the literature to differentiate introduced bacteria from indigenous microflora and to visualize them. These markers are presented together with the methods currently applied to quantify bacterial densities and to characterize the distribution of introduced bacteria. The methods to quantify bacterial densities are either based on bacterial cultivation or not. Different types…

Response of soil bacterial communities to the incorporation of crop residues : influence of agricultural practices and link with the soil biological …

2010

The effect of the location of wheat residues (soil surface vs. incorporated in soil) on their decomposition and on soil bacterial communities was investigated by the means of a field experiment. Bacterial-Automated Ribosomal Intergenic Spacer Analysis (B-ARISA) of DNA extracts from residues, detritusphere (soil adjacent to residues), and bulk soil evidenced that residues constitute the zone of maximal changes in bacterial composition. However, the location of the residues influenced greatly their decomposition and the dynamics of the colonizing bacterial communities. Sequencing of 16S rRNA gene in DNA extracts from the residues at the early, middle, and late stages of degradation confirmed …

A mathematical method for determining genome divergence and species delineation using AFLP.

2002

The delineation of bacterial species is presently achieved using direct DNA-DNA relatedness studies of whole genomes. It would be helpful to obtain the same genomically based delineation by indirect methods, provided that descriptions of individual genome composition of bacterial genomes are obtained and included in species descriptions. The amplified fragment length polymorphism (AFLP) technique could provide the necessary data if the nucleotides involved in restriction and amplification are fundamental to the description of genomic divergences. Firstly, in order to verify that AFLP analysis permits a realistic exploration of bacterial genome composition, the strong correspondence between …

Selection and integration of a new immunomodulatory probiotic strain in a food supplement

2012

Probiotics are live microorganisms that can act on the immune system at specific sites in the gastro-intestinal tract. From a technological point of view, the development of a dietary supplement containing viable and functional probiotics requires the control of the selection and production steps. In a first time, we have developed specific and sensitive screening tests to determine the ability of bacteria to be dried and the origin of its sensitivity. To develop these tests, we investigated the mechanisms involved during drying process. Thus, microorganisms simultaneously undergo osmotic stress and oxidative stress. Results show a strong impact of drying on the survival rate and immunomodu…

Response of soil bacterial communities to the incorporation of crop residues : influence of agricultural practices and link with the soil biological …

2010

The effect of the location of wheat residues (soil surface vs. incorporated in soil) on their decomposition and on soil bacterial communities was investigated by the means of a field experiment. Bacterial-Automated Ribosomal Intergenic Spacer Analysis (B-ARISA) of DNA extracts from residues, detritusphere (soil adjacent to residues), and bulk soil evidenced that residues constitute the zone of maximal changes in bacterial composition. However, the location of the residues influenced greatly their decomposition and the dynamics of the colonizing bacterial communities. Sequencing of 16S rRNA gene in DNA extracts from the residues at the early, middle, and late stages of degradation confirmed …

The syndrome "basses richesses" of sugar beet in France is associated with different pathogen types and insect vectors

2007

International audience; The syndrome “basses richesses” (SBR) of sugar beet in France is associated with two phloem-restricted uncultivable bacteria: a stolbur phytoplasma and a y-3 proteobacteria. The known vector of proteobacteria is a cixiid planthopper, Pentastiridius leporinus (Hemiptera Cixiidae), formerly shown to transmit both the prokaryotes. The role of P. leporinus and of two other planthopper species, Cixius wagneri and Hyalesthes obsoletus, in spreading the two pathogens to sugar beet were compared and quantified. Because of its abundance and high infection rates with proteobacterium, P. leporinus was confirmed to be the economic vector of SBR disease. P. leporinus and C. wagne…

Map gene as a new non ribosomal marker to study the molecular variability of grapevine yellows and related phytoplasmas from group 16SRV in Europe

2006

International audience

Vers la validation fonctionnelle du gène WEE1 dans l’acquisition de la résistance au stress abiotique chez des protéagineux

2017

Sequence typing of map, secY and degV genes confirm the genetic relatedness of three distinct groups of flavescence dorée phytoplasmas with phytoplas…

2006

International audience

Genomic approach to search for IPU degrading gene: catA as a possible gene target responsible for 4- isopropyl aniline degradation

2009

Affiche, résumé étendu; Genomic approach to search for IPU degrading gene: catA as a possible gene target responsible for 4- isopropyl aniline degradation