Publications

4852

Abstract We used phenotypic, genomic and phylogenetic information following the taxono-genomics approach to demonstrate that strain Marseille–P3254, isolated from an ileal sample of a 76-year old woman who underwent upper and lower digestive tract endoscopy for esophagitis and colonic polyp, is representative of a novel bacterial genus within the family Erysipelotrichaceae in the phylum Firmicutes. It is an anaerobic Gram-negative bacterium without catalase and oxidase activities. The genome of strain Marseille–P3254 is 2,468,496-bp long with a 40.1% G + C content. This new bacterium is most closely related to Eubacterium dolichum, with which it shares 90.7% 16S rRNA sequence similarity. In addition, genomic comparison using the digital DNA–DNA hybridization and OrthoANI analyses between the novel organism and the E. dolichum type strain revealed identities of 25.2 and 68.91%, respectively. The major fatty acids were C16: 0, C18: 1n9 and C18: 0. Based on these data, we propose the creation of the new genus Merdibacter gen. nov., with strain Marseille-P3254T (=CSUR P3254 = DSM 103534) being the type strain of the new species Merdibacter massiliensis gen. nov., sp. nov.

A novel anaerobic ammonium-oxidizing (anammox) bacterium was detected in an upflow column reactor treating synthetic nitrogen-rich saline solution. Here, we assembled a 4.59-Mb draft genome sequence of this bacterium, identified as a member of the genus “ Candidatus Scalindua,” that has 84% nucleotide-level genomic similarity with the closest related anammox bacterium (“ Candidatus Scalindua rubra”).

“ Candidatus Serratia symbiotica” is a facultative bacterial symbiont of aphids that affects various ecological traits of the host insects. Here, we report the complete genome sequence of “ Candidatus Serratia symbiotica” strain IS, consisting of a 2,736,352-bp chromosome and an 82,605-bp plasmid, from the pea aphid Acyrthosiphon pisum .

Abstract With the aim of describing the human microbiota by the means of culture methods, culturomics was developed in order to target previously un‐isolated bacterial species and describe it via the taxono‐genomics approach. While performing a descriptive study of the human gut microbiota of the pygmy people, strain Marseille‐P4678 T has been isolated from a stool sample of a healthy 39‐year‐old pygmy male. Cells of this strain were Gram‐positive cocci, spore‐forming, non‐motile, catalase‐positive and oxidase‐negative, and grow optimally at 37°C under anaerobic conditions. Its 16S rRNA gene sequence exhibited 89.69% of sequence similarity with Parvimonas micra strain 3119 B T ( NR 036934.1), its phylogenetically closest species with standing in nomenclature. The genome of strain Marseille‐P4678 T is 2,083,161 long with 28.26 mol% of G+C content. Based on its phenotypic, biochemical, genotypic and proteomic profile, this bacterium was classified as a new bacterial genus and species Miniphocibacter massiliensis gen. nov., sp. nov. with the type strain Marseille‐P4678 T .

“ Ca. Nitrotoga” is a NOB of high environmental relevance, but physiological data exist for only a few representatives. Initially, it was detected in specialized niches of low temperature and low nitrite concentrations, but later on, its ubiquitous distribution revealed its critical role for N removal in engineered systems like WWTPs. In this study, we analyzed the competition between Nitrotoga and Nitrospira in bioreactors and identified conditions where the K strategist Ns. defluvii was almost replaced by Nitrotoga sp. BS. We show that the pH value is an important factor that regulates the composition of the nitrite-oxidizing enrichment with a dominance of Nitrotoga sp. BS versus Ns. defluvii at a neutral pH of 7.4 in combination with a temperature of 17°C. The physiological diversity of novel Nitrotoga cultures improves our knowledge about niche differentiation of NOB with regard to functional nitrification under suboptimal conditions.

As one group of the most important functional phosphorus removal organisms, “ Candidatus Accumulibacter,” affiliated with the Rhodocyclus group of the Betaproteobacteria , is a widely recognized and studied PAO in the field of biological wastewater treatment. The morphotypes and population structure of clade-level “ Candidatus Accumulibacter” were studied through novel FISH-staining-flow cytometry, which involved denitrifying phosphorus removal (DPR) achieving carbon and energy savings and simultaneous removal of N and P, thus inferring the different denitrifying phosphorus removal abilities of these clades. Additionally, based on this method, in situ quantification for specific polyphosphate-accumulating organisms (PAOs) enables a more efficient process and more accurate result. The establishment of FISH-staining-flow cytometry makes cell sorting of clade-level noncultivated organisms available.

Abstract The methyl-coenzyme M reductase (MCR) complex is a key enzyme in archaeal methane generation and has recently been proposed to also be involved in the oxidation of short-chain hydrocarbons including methane, butane, and potentially propane. The number of archaeal clades encoding the MCR continues to grow, suggesting that this complex was inherited from an ancient ancestor, or has undergone extensive horizontal gene transfer. Expanding the representation of MCR-encoding lineages through metagenomic approaches will help resolve the evolutionary history of this complex. Here, a near-complete Archaeoglobi metagenome-assembled genome (MAG; Ca. Polytropus marinifundus gen. nov. sp. nov.) was recovered from the deep subseafloor along the Juan de Fuca Ridge flank that encodes two divergent McrABG operons similar to those found in Ca. Bathyarchaeota and Ca. Syntrophoarchaeum MAGs. Ca. P. marinifundus is basal to members of the class Archaeoglobi, and encodes the genes for β-oxidation, potentially allowing an alkanotrophic metabolism similar to that proposed for Ca. Syntrophoarchaeum. Ca. P. marinifundus also encodes a respiratory electron transport chain that can potentially utilize nitrate, iron, and sulfur compounds as electron acceptors. Phylogenetic analysis suggests that the Ca. P. marinifundus MCR operons were horizontally transferred, changing our understanding of the evolution and distribution of this complex in the Archaea.