Search results for "Alphaproteobacteria"
showing 10 items of 23 documents
So close, so different: geothermal flux shapes divergent soil microbial communities at neighbouring sites
2016
This study is focused on the (micro)biogeochemical features of two close geothermal sites (FAV1 and FAV2), both selected at the main exhalative area of Pantelleria Island, Italy. A previous biogeochemical survey revealed high CH4 consumption and the presence of a diverse community of methanotrophs at FAV2 site, whereas the close site FAV1 was apparently devoid of methanotrophs and recorded no CH4 consumption. Next-Generation Sequencing (NGS) techniques were applied to describe the bacterial and archaeal communities which have been linked to the physicochemical conditions and the geothermal sources of energy available at the two sites. Both sites are dominated by Bacteria and host a negligib…
Ant crickets and their secrets: Myrmecophilus acervorum is not always parthenogenetic (Insecta: Orthoptera: Myrmecophilidae)
2021
Abstract Previously considered as a thelytokous parthenogenetic species, the widespread ant cricket Myrmecophilus acervorum actually turns out to have a mixed reproductive system: our recent surveys in the central part of its distribution area has revealed the presence of both sexes. Detailed morphological and morphometric descriptions of the previously unknown males are here provided. New data on species distribution in south-eastern Europe are presented, including the first records of M. balcanicus in Bulgaria and of M. nonveilleri in Bulgaria and Hungary. Phylogenetic and phylogeographic analyses have revealed several haplotypes of M. acervorum in Europe, with six of them forming a parth…
Metagenomes of Mediterranean Coastal Lagoons
2012
Coastal lagoons, both hypersaline and freshwater, are common, but still understudied ecosystems. We describe, for the first time, using high throughput sequencing, the extant microbiota of two large and representative Mediterranean coastal lagoons, the hypersaline Mar Menor, and the freshwater Albufera de Valencia, both located on the south eastern coast of Spain. We show there are considerable differences in the microbiota of both lagoons, in comparison to other marine and freshwater habitats. Importantly, a novel uncultured sulfur oxidizing Alphaproteobacteria was found to dominate bacterioplankton in the hypersaline Mar Menor. Also, in the latter prokaryotic cyanobacteria were almost exc…
Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)
2014
Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a−1 (t a−1). Laboratory incubation experiments with three top-soil samples from …
Eukaryotes Are a Holophyletic Group of Polyphyletic Origin.
2020
Because of the polyphyletic origin of the eukaryotic monophylum, eukaryogenesis within prokaryotes is not comparable with mammal origin within paraphyletic reptiles. Both synapomorphies and plesiomorphies represent apomorphies and are indeed suitable for defining monophyletic (holophyletic and paraphyletic) groups. Alphaproteobacteria (Bacteria) and Asgard (Archaea) are the ancestors of LECA (the Last Eukaryotic Common Ancestor). The presence of ESPs in Asgard does not dispute the polyphyletic origin of eukaryotes ; it only further corroborates it. “Candidatus Prometheoarchaeum syntrophicum” is the closest relative to eukaryotes and the only Asgard with available microscopy data. This newly…
Isolation and Characterization of Novosphingobium sp. Strain MT1, a Dominant Polychlorophenol-Degrading Strain in a Groundwater Bioremediation System
2002
ABSTRACT A high-rate fluidized-bed bioreactor has been treating polychlorophenol-contaminated groundwater in southern Finland at 5 to 8°C for over 6 years. We examined the microbial diversity of the bioreactor using three 16S ribosomal DNA (rDNA)-based methods: denaturing gradient gel electrophoresis, length heterogeneity-PCR analysis, and restriction fragment length polymorphism analysis. The molecular study revealed that the process was dependent on a stable bacterial community with low species diversity. The dominant organism, Novosphingobium sp. strain MT1, was isolated and characterized. Novosphingobium sp. strain MT1 degraded the main contaminants of the groundwater, 2,4,6-trichloroph…
Nereida ignava gen. nov., sp. nov., a novel aerobic marine alpha-proteobacterium that is closely related to uncultured Prionitis (alga) gall symbiont…
2005
A Gram-negative, slightly halophilic, non-pigmented, strictly aerobic, chemo-organotrophic bacterium was isolated from Mediterranean sea water off the Spanish coast near Valencia. This strain was poorly reactive, being unable to grow in most carbon sources analysed in minimal medium. However, good growth was observed when more complex media and longer incubation times were used. Phylogenetic analysis based on an almost complete 16S rRNA gene sequence placed strain 2SM4T within the Roseobacter group, in the vicinity of uncultured bacteria described as gall symbionts of several species of the red alga Prionitis. Sequence similarity values between strain 2SM4T and the closest neighbouring spec…
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…
Methanotrophy induces nitrogen fixation during peatland development
2013
Significance In peatlands, the external sources of nitrogen are mainly atmospheric, but the atmospheric nitrogen deposition alone cannot explain the long-term annual nitrogen accumulation rates to these ecosystems. Because of methodological problems, methane-induced fixation of atmospheric dinitrogen gas has been previously overlooked as an additional nitrogen input mechanism. We found that the activity of methane-oxidizing bacteria provides not only carbon but also nitrogen to peat mosses and, thus, contributes to carbon and nitrogen accumulation in peatlands, which store approximately one-third of the global soil carbon pool. Our results imply that nitrogen fixation in wetlands may be str…
Identification of the Weevil immune genes and their expression in the bacteriome tissue
2008
Abstract Background Persistent infections with mutualistic intracellular bacteria (endosymbionts) are well represented in insects and are considered to be a driving force in evolution. However, while pathogenic relationships have been well studied over the last decades very little is known about the recognition of the endosymbionts by the host immune system and the mechanism that limits their infection to the bacteria-bearing host tissue (the bacteriome). Results To study bacteriome immune specificity, we first identified immune-relevant genes of the weevil Sitophilus zeamais by using suppressive subtractive hybridization (SSH) and then analyzed their full-length coding sequences obtained b…