Search results for "rDNA"
showing 10 items of 73 documents
Analisi della comunità microbica intestinale di Reticulitermes lucifugus (Rossi) (Isoptera: Rhinotermitidae).
2009
L’intestino delle termiti ospita una comunità microbica di batteri e flagellati anaerobi, responsabile della degradazione del materiale lignocellulosico. La digestione della lignocellulosa da parte delle termiti dipende dalla simbiosi con microrganismi procarioti ed eucarioti che vivono nel loro intestino. I microrganismi trasformano la cellulosa in zuccheri e acetato, producendo idrogeno, metano e anidride carbonica. Abbiamo analizzato la comunità microbica intestinale di Reticulitermes lucifugus lucifugus, una delle due specie di termiti italiane, che vive in ambienti sotterranei, è distruttiva per le strutture legnose degli ambienti urbani causando seri danni ai monumenti storici e può c…
DNA analysis as tool for identification of bacteria in archaeological watellogged wood
2014
S32. Wooden artifacts: from wood identification to dating and conservation/restoration strategies DNA analysis as tool for identification of bacteria in archaeological waterlogged wood Palla, Franco; University of Palermo; Palermo; Italy Barresi, Giovanna; University of Palermo; Palermo; Italy Di Carlo, Enza; University of Palermo; Palermo; Italy In this work molecular techniques were applied in order to integrate the results obtained by Optical (OM) and Scanning Electron (SEM) Microscopy, to understanding and assessing the changes in the anatomical structure of archaeological waterlogged wood (Pinus sp.) induced by bacteria colonization. Observation of wooden thin sections by OM showed the…
Candida pararugosa isolation from the oral cavity of an Italian denture wearer
2004
Candida pararugosa was first isolated from human feces, but after the initial description no further recovery from humans has been reported. During a study on oral Candida colonization in denture wearers living in Palermo (Italy), we isolated C. pararugosa from a 61-year-old woman without signs of oral candidosis. This constitutes, to the authors' knowledge, the first isolation of C. pararugosa from the oral cavity. After six months, colonization by C. pararugosa persisted, suggesting that this species could be a component of the normal oral microbiota. The identification procedure we used could be useful in elucidating the epidemiology of C. pararugosa and for establishing its clinical sig…
A mitochondrial phylogeography of Brachidontes variabilis (Bivalvia: Mytilidae) reveals three cryptic species
2007
This study examined genetic variation across the range of Brachidontes variabilis to produce a molecular phylogeography. Neighbour joining (NJ), minimum evolution (ME) and maximum parsimony (MP) trees based on partial mitochondrial DNA sequences of 16S-rDNA and cytochrome oxidase (COI) genes revealed three monophyletic clades: (1) Brachidontes pharaonis s.l. from the Mediterranean Sea and the Red Sea; (2) B. variabilis from the Indian Ocean; (3) B. variabilis from the western Pacific Ocean. Although the three clades have never been differentiated by malacologists employing conventional morphological keys, they should be ascribed to the taxonomic rank of species. The nucleotide divergences b…
Medicago species affect the community composition of arbuscular mycorrhizal fungi associated with roots
2007
National audience; The symbiosis between plants and arbuscular mycorrhizal fungi (AMF) is ancient and involves 80% of terrestrial plant families. The symbiotic association between AMF and plants was described to be non specific. However, AMF were reported to influence plant community diversity and productivity. On the other way, the effect of plant genotypes belonging to closely related species on AMF diversity has not been explored so far. The aim of this work was to assess the impact of four different Medicago species, M. laciniata, M. murex, M. polymorpha and M. truncatula cv. Jemalong J5, on the composition of AM fungal community, when cultivated in a silty-thin clay soil (Mas d’Imbert,…
Microalgae community structure analysis based on 18S rDNA amplification from DNA extracted directly from soil as a potential soil bioindicator
2005
International audience; Soil algae are photosynthetically active microorganisms showing changeable community structure, depending on the soil type, the agricultural practices and the application of pesticides. To characterise algal community structure, molecular approaches complementary to classical microbiological approaches based on the isolation and the culture of soil algae are required. Our study describes a polymerase chain reaction (PCR) approach targeting algal 18S rDNA sequences of desoxyribonucleic acid (DNA) samples extracted either from unialgal eukaryotic microalgae culture, complex assemblages of microalgae populations or natural soil communities. Our first results showed that…
Characterization of rhizobia nodulating chickpea in Tunisia
2001
Cent cinquante rhizobia nodulant le pois chiche (Cicer arietinum L.) ont ete isoles a partir de sols echantillonnes dans differentes regions de Tunisie. L'inoculation de la plante hote avec ces isolats montre une variabilite dans le temps d'apparition des premieres nodosites. Cinq isolats induisent des nodosites deux semaines apres inoculation alors que pour les 145 isolats restants les nodosites ne sont observees qu'apres au moins quatre semaines. L'etude par PCR/RFLP de l'ADNr 16S a permis de rattacher les isolats du premier groupe a l'espece Mesorhizobium mediterraneum et ceux du second groupe a l'espece Sinorhizobium medicae. La position taxonomique des isolats a ete confirmee par leurs…
Wet-up response of the microbial community is shaped by soil dry-down patterns
2015
Background/Question/Methods The massive soil CO2 efflux associated with rewetting dry soils after the dry summer period significantly contributes to the annual carbon budget of Mediterranean grasslands. Rapid reactivation of soil heterotrophic activity and available carbon are both required to fuel the CO2 pulse. Better understanding of the effects of altered summer precipitation on the metabolic state of indigenous microorganisms may be important in predicting future changes in carbon cycling. We investigated the effects of a controlled rewetting event on the soil CO2efflux pulse and on the present (DNA-based) and potentially active (rRNA-based) soil bacterial and fungal communities in int…
Changing summer precipitation pattern alters microbial community response to fall wet-up in a Mediterranean soil
2014
The large soil CO2 efflux associated with rewetting dry soils after the dry summer period significantly contributes to the annual carbon budget of Mediterranean grasslands. Rapid reactivation of soil heterotrophic activity and a pulse of available carbon are both required to fuel the CO2 pulse. Better understanding of the effects of altered summer precipitation on the metabolic state of indigenous microorganisms may be important in predicting future changes in carbon cycling. Here, we investigated the effects of a controlled rewetting event on the soil CO2 efflux pulse and on the present (DNA-based) and potentially active (rRNA-based) soil bacterial and fungal communities in intact soil cor…
Diversity of arbuscular mycorrhizal fungi (Glomeromycota) in european soils analysed by pyrosequencing
2012
Arbuscular mycorrhiza provides essential ecosystem functions in natural and humandominated ecosystems. Generally human activities like agriculture seem to have a negative effect on diversity of arbuscular mycorrhizal fungi (AMF), and thus on ecosystem functioning. New sequencing technologies now allow to assess AMF diversity on a much larger scale than previously. In the context of the European project EcoFINDERS, five Long-Term Observatories across Europe with different soil management have been studied. The diversity of AMF in these soils is analyzed by pyrosequencing, using the ITS (rDNA Internal Transcribed Spacers) as marker, which were recently determined as the standard barcoding gen…