Methanogens are important hydrogen consumers in the gut and are associated with differing host health. Here, we determine the prevalence and abundance of archaeal species in the guts of a multi-ethnic cohort of healthy Singapore residents.
Here, we report draft genome sequences for nine strains of “
Candidatus
Nanosynbacter sp. HMT-352.” These strains and their sequences were used to interrogate strain-level variations in host range, gene content, and growth dynamics among the phylum “
Candidatus
Saccharibacteria.”
AbstractCandidatus Branchiomonas cysticola is an intracellular, gram-negative Betaproteobacteria causing epitheliocystis in Atlantic Salmon (Salmo salar L.). The bacterium has not been genetically characterized at the intraspecific level despite its high prevalence among salmon suffering from gill disease in Norwegian aquaculture. DNA from gill samples of Atlantic salmon PCR positive for Cand. B. cysticola and displaying pathological signs of gill disease, was, therefore, extracted and subject to next-generation sequencing (mNGS). Partial sequences of four housekeeping (HK) genes (aceE, lepA, rplB, rpoC) were ultimately identified from the sequenced material. Assays for real-time RT-PCR and fluorescence in-situ hybridization, targeting the newly acquired genes, were simultaneously applied with existing assays targeting the previously characterized 16S rRNA gene. Agreement in both expression and specificity between these putative HK genes and the 16S gene was observed in all instances, indicating that the partial sequences of these HK genes originate from Cand. B. cysticola. The knowledge generated from the present study constitutes a major prerequisite for the future design of novel genotyping schemes for this bacterium.
“CandidatusAccumulibacter” is the most studied PAO, with a primary role in biological nutrient removal. However, the species-level taxonomy of this lineage is convoluted due to the use of different phylogenetic markers or genome sequencing approaches. Here, we redefined the phylogeny of these organisms, proposing a comprehensive approach which could be used to address the classification of other diverse and uncultivated lineages.
AbstractAsgard archaea have recently been identified as the closest archaeal relatives of eukaryotes. Their ecology, and particularly their virome, remain enigmatic. We reassembled and closed the chromosome of Candidatus Odinarchaeum yellowstonii LCB_4, through long-range PCR, revealing CRISPR spacers targeting viral contigs. We found related viruses in the genomes of diverse prokaryotes from geothermal environments, including other Asgard archaea. These viruses open research avenues into the ecology and evolution of Asgard archaea.
Saccharibacteria
are abundant and diverse members of the human oral microbiome; however, they are poorly understood and appear to exhibit an epibiont/parasitic lifestyle dependent on host bacteria. Here, a complete metagenome-assembled genome (MAG) sequence of an organism from
Saccharibacteria
clade G1 human microbial taxon (HMT) 348 is reported, strain HMT-348_TM7c-JB.
“Cand. Nanosynbacter
sp. HMT352” strain KC1 is an ectoparasitic saccharibacterium/TM7 that was co-isolated from a human saliva sample with its obligate bacterial host,
Schaalia odontolytica
. The genome of strain KC1 enables studies of the mechanisms and evolution of interspecies interactions and, for oral species, studies of their potential roles in health and disease.