Search results for "polymorph"
showing 10 items of 2115 documents
Molecular analysis of the catechol-degrading bacterial community in a coal wasteland heavily contaminated with PAHs
2010
International audience; A PCR-based molecular tool was developed to estimate the diversity of the catechol-degrading bacterial community in a coal wasteland heavily contaminated with PAHS. A degenerate primer pair specific to catA sequences was designed by multiple alignment of known sequences coding a key intermediate of the β-ketoadiapate pathway degrading catechol, namely catechol 1,2-dioxygenase. The specificity of this primer pair was assessed in 21 pure strains by PCR and sequencing. Comparison of the 16S rDNA and catA phylogenies revealed an absence of congruence between these two genes. The primer set was able to amplify catA sequences in DNA extracts from an industrial soil highly …
Virulence and Molecular Typing of Vibrio harveyi Strains Isolated from Cultured Dentex, Gilthead Sea Bream and European Sea Bass
2003
Vibrio harveyi was isolated from internal organs or ulcers of diseased and apparently healthy gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax) cultured in several fish farms located on the Spanish Mediterranean coast. The prevalence of the bacterium was significantly higher in European sea bass than in gilthead sea bream, and was closely related to the season in both fish species, occurring almost exclusively on warm months (June to November). After phenotypic characterization, a selection of forty five isolates from gilthead sea bream, sea bass, and several isolates previously obtained from common dentex (Dentex dentex) of the same area, were molecularly type…
Evidence of Genomic Instability in Campylobacter jejuni Isolated from Poultry
1998
ABSTRACT Poultry isolates of Campylobacter jejuni derived from a survey of meat processing batches were genotyped by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA to establish the clonal relationships between single-colony isolates. In the majority of batches studied, one or two genotype patterns predominated. However, in one batch (batch A), 21 single-colony isolates gave 14 different PFGE genotypes. The banding patterns obtained with Sma I were sufficiently different to distinguish between genotypes, although the patterns also produced many common bands. The question of whether these isolates represented different clones or had a common clonal ancestry was addressed by additi…
Identification of Carnobacterium, Lactobacillus, Leuconostoc and Pediococcus by rDNA-based techniques
2003
Summary Ribosomal DNA-based techniques including the analysis of profiles generated by ISR amplification, ISR restriction and ARDRA have been evaluated as molecular tools for identifying Carnobacterium, Lactobacillus, Leuconostoc and Pediococcus. They have been applied for the molecular characterization of 91 strains with the following identities: eight Carnobacterium including the eight type species of the genus; 61 Lactobacillus including 40 type strains out of 45 species, 13 Leuconostoc, out of them 11 are type strains and three are subspecies of Lc. mesenteroides; and nine strains representing the six species of genus Pediococcus. The genetic relationship displayed between these species…
Diversity of rhizobia nodulating wild shrubs of Sicily and some neighbouring islands
2008
Abstract Legume shrubs have great potential for rehabilitation of semi-arid degraded soils in Mediterranean ecosystems as they establish mutualistic symbiosis with Nfxing rhizobia. Eighty-eight symbiotic rhizobia were isolated from seven wild legume shrubs native of Sicily (Southern Italy) and grouped in operational taxonomic units (OTU) by analysis of the ribosomal internal transcribed spacer (ITS) polymorphism. Partial sequencing of 16S rRNA gene of representative isolates of each OTU revealed that most Genisteae symbionts are related to Bradyrhizobium canariense, B. japonicum and B. elkanii. Teline monspessulana was the only Genistea nodulated by Mesorhizobium strains, and Anagyris foeti…
Lactobacillus aquaticus sp. nov., isolated from a Korean freshwater pond.
2009
A Lactobacillus strain, IMCC1736T, was isolated recently from a Korean freshwater pond following an extensive study of the microbial community in this ecosystem. Its 16S rRNA gene was sequenced and phylogenetic analysis placed this strain within the Lactobacillus salivarius group, closely related to Lactobacillus satsumensis NRIC 0604T, with 97.9% sequence similarity. In the present work, the taxonomic status of strain IMCC1736T has been re-evaluated. It was characterized phylogenetically, genotypically and phenotypically and, based on DNA-DNA hybridization values, this strain represents a novel Lactobacillus species. Strain IMCC1736T can be differentiated genotypically from its closest rel…
Genotypic characterization of Bradyrhizobium strains nodulating small Senegalese legumes by 16S-23S rRNA intergenic gene spacers and amplified fragme…
2000
ABSTRACT We examined the genotypic diversity of 64 Bradyrhizobium strains isolated from nodules from 27 native leguminous plant species in Senegal (West Africa) belonging to the genera Abrus , Alysicarpus , Bryaspis , Chamaecrista , Cassia , Crotalaria , Desmodium , Eriosema , Indigofera , Moghania , Rhynchosia , Sesbania , Tephrosia , and Zornia , which play an ecological role and have agronomic potential in arid regions. The strains were characterized by intergenic spacer (between 16S and 23S rRNA genes) PCR and restriction fragment length polymorphism (IGS PCR-RFLP) and amplified fragment length polymorphism (AFLP) fingerprinting analyses. Fifty-three reference strains of the different B…
Conservation of type III secretion system genes inBradyrhizobiumisolated from soybean
2006
International audience; The distribution of rhcRST genes encoding the type III secretion system (T3SS) in a collection of Bradyrhizobium strains was characterized by PCR and Southern blot hybridization. The polymorphism of the corresponding sequences amplified by PCR was characterized by RFLP and sequencing together with those available in the databank. Genomic group I is characterized by the presence of Bradyrhizobium elkanii strains and group II by the presence of B. japonicum and B. liaoningense strains. Highly conserved T3SS-like genes were detected by PCR in all Bradyrhizobium strains isolated from soybean belonging to genomic group II, and in none of the strains belonging to genomic g…
Biodiversity and dairy traits of lactic acid bacteria from foliage of aromatic plants before and after dehydration process monitored by a smart senso…
2020
ABSTRACT The main hypothesis of this work was to evaluate the presence of lactic acid bacteria (LAB) intrinsically resistant to plant essential oils in sage (Salvia officinalis L.) and laurel (Laurus nobilis), for future applications in functional cheese production by addition of aromatic herbs. The effect of the drying process on the viability of LAB was evaluated with three biomass densities (3, 4 and 5 kg/m2). The drying densities did not affect weight loss, but influenced the levels of LAB of sage and laurel. A total of 10 different strains of Enterococcus faecium, Enterococcus mundtii, Enterococcus raffinosus and Leuconostoc mesenteroides were identified from laurel, while sage did not…
Polyphasic study of wine Lactobacillus strains: taxonomic implications
2005
One hundred and seventy-eight lactobacilli isolated from wine were characterized by a polyphasic approach. Strains were phenotypically identified at genus and species level by classical tests including the analysis of cell morphology, homo/heterofermentative character, sugar fermentation patterns, growth at different temperatures and the optical nature of the isomer of lactic acid produced from glucose. Molecular techniques such as random amplification of polymorphic DNA (RAPD), amplified 16S rDNA restriction analysis (16S-ARDRA), PFGE-RFLP and ribotyping were used to characterize strains, and their potential for identification and/or typing was evaluated. The information obtained with thes…