Search results for "phylogeny"
showing 10 items of 1398 documents
Bermanella marisrubri gen. nov., sp. nov., a genome-sequenced gammaproteobacterium from the Red Sea
2009
5 pages, 2 figures, 1 table
Molecular characterization of the black Aspergillus isolates responsible for ochratoxin A contamination in grapes and wine in relation to taxonomy of…
2009
This work examines ochratoxigenic mycobiota in grapes by ap-PCR analysis sequence analysis of the ITS and IGS regions and ability to produce OTA. A comparison was also made with many reference strains of Aspergillus section Nigri. Based on ap-PCR profiles, derived from two microsatellite primers, three main groups were obtained by UPGMA cluster analysis corresponding to A. carbonarius, A. niger and A. tubingensis. The cophenetic correlation values corresponding to ap-PCR UPGMA analysis revealed a higher genetic variability in A. niger and A. tubingensis than in A. carbonarius. In addition, no genotypical differences could be established between OTA producers and nonproducers in all species …
A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily.
2008
Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based …
Melastomeae come full circle: biogeographic reconstruction and molecular clock dating.
2001
Rhexia, with 11 species in the Coastal Plain province of North America, is the only temperate zone endemic of the tropical eudicot family Melastomataceae. It is a member of the only pantropical tribe of that family, Melastomeae. Based on the chloroplast gene ndhF, we use a fossil-calibrated molecular clock to address the question of the geographic origin and age of Rhexia. Sequences from 37 species in 21 genera representing the tribe's geographical range were analyzed together with five outgroups. To obtain better clade support, another chloroplast region, the rpl16 intron, was added for 24 of the species. Parsimony analysis of the combined data and maximum-likelihood analysis of ndhF alone…
Genetic characterization of the nitrate reducing community based on narG nucleotide sequence analysis.
2003
The ability of facultative anerobes to respire nitrate has been ascribed mainly to the activity of a membrane-bound nitrate reductase encoded by the narGHJI operon. Respiratory nitrate reduction is the first step of the denitrification pathway, which is considered as an important soil process since it contributes to the global cycling of nitrogen. In this study, we employed direct PCR, cloning, and sequencing of narG gene fragments to determine the diversity of nitrate-reducing bacteria occurring in soil and in the maize rhizosphere. Libraries containing 727 clones in total were screened by restriction fragment analysis. Phylogenetic analysis of 128 narG sequences separated the clone famili…
Molecular Characterization of the Leucine Plasmid from Buchnera aphidicola , Primary Endosymbiont of the Aphid Acyrthosiphon pisum
2000
The complete sequence of the leucine plasmid of Buchnera aphidicola from the aphid Acyrthosiphon pisum (pLeu-BAp) is reported. Its gene organization was concordant with those of other leucine plasmids of Buchnera from aphids of the Aphidini and Macrosiphini tribes. Three inverted repeats are present in pLeu-BAp. Two of them are also present in pLeu from the family Aphididae: (i) SIR1, located downstream the leucine operon, resembles a rho-independent terminator of transcription, and (ii) LIR1, located upstream of the leucine operon, is suggested to be involved in transcription termination or messenger stability. The third, located near the putative ATGC repeats involved in the origin of rep…
Phylogeny and morphology of Hirsutella tunicata sp. nov. (Ophiocordycipitaceae), a novel mite parasite from Peru
2013
Abstract A new species of Hirsutella was isolated from unidentified mites on Petri plates inoculated with soil and root fragments collected from asparagus rhizosphere at Viru, Northern Peru. The fungus differs from other Hirsutella species by an envelope surrounding the conidium, conidia dimension and DNA sequences. In PDA cultures, the mycelium produced aerial hyphae with conidiogenous cells mainly at right angles, occasionally showing a secondary conidiophore. The solitary conidia are cymbiform, slightly apiculate, 5.0–6.0 × 3.0–4.0 μm. Phylogenetic analyses with partial rRNA and β-tubulin gene sequences confirmed the fungus as an Hirsutella (Ophiocordycipitaceae). Closest species shown b…
Stappia alba sp. nov., isolated from Mediterranean oysters
2005
Abstract Three bacterial strains isolated from oysters recovered at the Spanish Mediterranean coast have been phenotypically and genetically characterized. The results of the phylogenetic analysis based on almost complete 16S rDNA sequences clustered all three strains together with 99.9% average sequence similarity and situated them in the neighbourhood of the genera Stappia , Roseibium and Pannonibacter , Stappia aggregata being their closest neighbour with sequence similarities between 98.8% and 98.9%. DNA–DNA hybridization experiments using DNA of strains 5OM6 T and S. aggregata CECT 4269 T as reference DNAs confirmed the independent status at species level of the oyster isolates. Phenot…
Early human peopling of Sicily: Evidence from the Mesolithic skeletal remains from Grotta d'Oriente
2010
The site of Grotta d'Oriente, Island of Favignana, Sicily has yielded the complete skeleton of an adult female (OB) dated to the Mesolithic age. The cranial morphometry of this individual can provide us with some useful information about the peopling of Sicily in the Early Holocene period.Morphological affinities of OB and other Sicilian Mesolithic specimens were assessed to verify hypotheses concerning the early peopling of Sicily.Craniofacial metric data were employed in a comparative analysis with European Upper Palaeolithic (UP), Mesolithic, Neolithic, and Copper/Bronze age samples, and contemporary Italians. Both a model-free and a model-bound approach were used not only to calculate c…
Retama species growing in different ecological-climatic areas of northeastern Algeria have a narrow range of rhizobia that form a novel phylogenetic …
2009
International audience; Sixty-seven isolates were isolated from nodules collected on roots of Mediterranean shrubby legumes Retama raetam and Retama sphaerocarpa growing in seven ecological-climatic areas of northeastern Algeria. Genetic diversity of the Retama isolates was analyzed based on genotyping by restriction fragment length polymorphism of PCR-amplified fragments of the 16S rRNA gene, the intergenic spacer (IGS) region between the 16S and 23S rRNA genes (IGS), and the symbiotic genes nifH and nodC. Eleven haplotypes assigned to the Bradyrhizobium genus were identified. Significant biogeographical differentiation of the rhizobial populations was found, but one haplotype was predomin…