Search results for "archaea"

Novel Glutamate–Putrescine Ligase Activity in Haloferax mediterranei: A New Function for glnA-2 Gene

2021

This article belongs to the Section Cellular Biochemistry.

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…

Microbial communities of the Mediterranean rocky coast: ecology and biotechnological potential

2018

AbstractMicrobial communities from harsh environments hold great promise as sources of biotechnologically-relevant strains. In the present work, we have deeply characterized the microorganisms from three different rocky locations of the Mediterranean coast, an environment characterised by being subjected to harsh conditions such as high levels of irradiation and large temperature and salinity fluctuations. Through culture-dependent and culture-independent techniques, we have retrieved a complete view of the ecology and functional aspects of these communities and assessed the biotechnological potential of the cultivable microorganisms. A culture-independent approach through high-throughput 1…

Archaea in boreal Swedish lakes are diverse, dominated by Woesearchaeota and follow deterministic community assembly

2020

Despite their key role in biogeochemical processes, particularly the methane cycle, archaea are widely underrepresented in molecular surveys because of their lower abundance compared to bacteria and eukaryotes. Here, we use parallel high‐resolution small subunit rRNA gene sequencing to explore archaeal diversity in 109 Swedish lakes and correlate archaeal community assembly mechanisms to large‐scale latitudinal, climatic (nemoral to arctic), and nutrient (oligotrophic to eutrophic) gradients. Sequencing with universal primers showed the contribution of archaea was on average 0.8% but increased up to 1.5% of the three domains in forest lakes. Archaea‐specific sequencing revealed that freshwa…

High-Throughput Mapping of 2′-O-Me Residues in RNA Using Next-Generation Sequencing (Illumina RiboMethSeq Protocol)

2017

Detection of RNA modifications in native RNAs is a tedious and laborious task, since the global level of these residues is low and most of the suitable physico-chemical methods require purification of the RNA of interest almost to homogeneity. To overcome these limitations, methods based on RT-driven primer extension have been developed and successfully used, sometimes in combination with a specific chemical treatment. Nowadays, some of these approaches have been coupled to high-throughput sequencing technologies, allowing the access to transcriptome-wide data. RNA 2'-O-methylation is one of the ubiquitous nucleotide modifications found in many RNA types from bacteria, archaea, and eukarya.…

Cell Wall Structures of Mesophilic, Thermophilic and Hyperthermophilic Archaea

2006

Origin and phylogenetic relationships of [4Fe–4S]‐containing O 2 sensors of bacteria

2018

The advent of environmental O2 about 2.5 billion years ago forced microbes to metabolically adapt and to develop mechanisms for O2 sensing. Sensing of O2 by [4Fe-4S]2+ to [2Fe-2S]2+ cluster conversion represents an ancient mechanism that is used by FNREc (Escherichia coli), FNRBs (Bacillus subtilis), NreBSa (Staphylococcus aureus) and WhiB3Mt (Mycobacterium tuberculosis). The phylogenetic relationship of these sensors was investigated. FNREc homologues are restricted to the proteobacteria and a few representatives from other phyla. Homologues of FNRBs and NreBSa are located within the bacilli, of WhiB3 within the actinobacteria. Archaea contain no homologues. The data reveal no similarity b…

Aerobic Endospore-forming Bacteria and Soil Invertebrates

2011

The intestinal microbiotas of only a few soil invertebrates such as collembola (springtails), earthworms, nematodes, isopods (woodlice and pill bugs), millipedes and termites have been studied by classical and molecular methods in the last decades. It became obvious that these lower members of the soil biota harbour complex microbial communities that sometimes reach counts of 1011 cells ml−1 in their intestinal tracts. The gut microbiotas of the soil fauna include a variety of microorganisms from all three domains of life (Bacteria, Archaea, Eucarya). The bacterial species can mainly be assigned to the Gram-positive phyla Firmicutes and Actinobacteria as well as the Gram-negative phyla Prot…

Optogenetically blocking sharp wave ripple events in sleep does not interfere with the formation of stable spatial representation in the CA1 area of …

2016

During hippocampal sharp wave/ripple (SWR) events, previously occurring, sensory inputdriven neuronal firing patterns are replayed. Such replay is thought to be important for plasticity-related processes and consolidation of memory traces. It has previously been shown that the electrical stimulation-induced disruption of SWR events interferes with learning in rodents in different experimental paradigms. On the other hand, the cognitive map theory posits that the plastic changes of the firing of hippocampal place cells constitute the electrophysiological counterpart of the spatial learning, observable at the behavioral level. Therefore, we tested whether intact SWR events occurring during th…

Comprehensive dataset of shotgun metagenomes from oxygen stratified freshwater lakes and ponds

2021

Stratified lakes and ponds featuring steep oxygen gradients are significant net sources of greenhouse gases and hotspots in the carbon cycle. Despite their significant biogeochemical roles, the microbial communities, especially in the oxygen depleted compartments, are poorly known. Here, we present a comprehensive dataset including 267 shotgun metagenomes from 41 stratified lakes and ponds mainly located in the boreal and subarctic regions, but also including one tropical reservoir and one temperate lake. For most lakes and ponds, the data includes a vertical sample set spanning from the oxic surface to the anoxic bottom layer. The majority of the samples were collected during the open wate…