Morphology and ultrastructure of Crenothrix polyspora Cohn

Völker, Horst; Schweisfurth, R.; Hirsch, Peter

doi:10.1128/jb.131.1.306-313.1977

Cited by 42 publications

(10 citation statements)

References 17 publications

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“…The species is listed under family Crenotrichaceae in the List of Prokaryotic Names with Standing in Nomenclature (Parte, 2014) but has been transferred to Methylococcaceae in the most recent edition of the Bergey’s Manual of Systematics of Archaea and Bacteria (Bowman, 2016a). Although C. polyspora is multicellular and filamentous, its assignment to Methylococcaceae is consistent with the occurrence of intracytoplasmic membrane stacks and their arrangement as vesicular discs (Völker et al, 1977; Stoecker et al, 2006), as well as the placement of the species within the family based on 16S rRNA phylogeny (Figure 1A and Supplementary Figure S1A; Völker et al, 1977; Stoecker et al, 2006; Vigliotta et al, 2007; Knief, 2015; Bowman, 2016a; Oswald et al, 2017). Indeed, the genome phylogeny shows the three Crenothrix genomes ( C. polyspora RSM_CP1 and RSM_CP2 and Crenothrix sp.…”

Section: Resultssupporting

confidence: 60%

Phylogenomic Analysis of the Gammaproteobacterial Methanotrophs (Order Methylococcales) Calls for the Reclassification of Members at the Genus and Species Levels

et al. 2018

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The order Methylococcales constitutes the methanotrophs – bacteria that can metabolize methane, a potent greenhouse gas, as their sole source of energy. These bacteria are significant players in the global carbon cycle and can produce value-added products from methane, such as biopolymers, biofuels, and single-cell proteins for animal feed, among others. Previous studies using single-gene phylogenies have shown inconsistencies in the currently established taxonomic structure of this group. This study aimed to determine and resolve these issues by using whole-genome sequence analyses. Phylogenomic analysis and the use of similarity indexes for genomic comparisons – average amino acid identity, digital DNA–DNA hybridization (dDDH), and average nucleotide identity (ANI) – were performed on 91 Methylococcales genomes. Results suggest the reclassification of members at the genus and species levels. Firstly, to resolve polyphyly of the genus Methylomicrobium, Methylomicrobium alcaliphilum, “Methylomicrobium buryatense,” Methylomicrobium japanense, Methylomicrobium kenyense, and Methylomicrobium pelagicum are reclassified to a newly proposed genus, Methylotuvimicrobium gen. nov.; they are therefore renamed to Methylotuvimicrobium alcaliphilum comb. nov., “Methylotuvimicrobium buryatense” comb. nov., Methylotuvimicrobium japanense comb. nov., Methylotuvimicrobium kenyense comb. nov., and Methylotuvimicrobium pelagicum comb. nov., respectively. Secondly, due to the phylogenetic affinity and phenotypic similarities of Methylosarcina lacus with Methylomicrobium agile and Methylomicrobium album, the reclassification of the former species to Methylomicrobium lacus comb. nov. is proposed. Thirdly, using established same-species delineation thresholds (70% dDDH and 95% ANI), Methylobacter whittenburyi is proposed to be a later heterotypic synonym of Methylobacter marinus (89% dDDH and 99% ANI). Also, the effectively but not validly published “Methylomonas denitrificans” was identified as Methylomonas methanica (92% dDDH and 100% ANI), indicating that the former is a later heterotypic synonym of the latter. Lastly, strains MC09, R-45363, and R-45371, currently identified as M. methanica, each represent a putative novel species of the genus Methylomonas (21–35% dDDH and 74–88% ANI against M. methanica) and were reclassified as Methylomonas sp. strains. It is imperative to resolve taxonomic inconsistencies within this group, first and foremost, to avoid confusion with ecological and evolutionary interpretations in subsequent studies.

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Section: Resultssupporting

confidence: 60%

Phylogenomic Analysis of the Gammaproteobacterial Methanotrophs (Order Methylococcales) Calls for the Reclassification of Members at the Genus and Species Levels

et al. 2018

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“…Application of microscopy to view various mat samples from COP reveals that filamentous organisms represent the dominant morphotype. While originally we assumed these filaments represented sulfide oxidizers, several works [ Völker et al , 1977; Stoecher et al , 2006; Vigliotta et al , 2007] have shown the existence of filamentous, methanotrophic bacteria. While such organisms are currently known only in terrestrial environments we find it likely that similar organisms inhabit the mats described here.…”

Section: Discussionmentioning

confidence: 99%

Methanotrophic bacteria occupy benthic microbial mats in shallow marine hydrocarbon seeps, Coal Oil Point, California

Ding

Valentine

2008

J. Geophys. Res.

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[1] Microbial mats composed of giant sulfur bacteria are observed throughout the benthos along continental margins. These communities serve to oxidize dissolved sulfides to sulfate, and are typically associated with the recent exposure of sulfide-rich sediments. Such mats are also ubiquitous in areas of hydrocarbon seepage, where they are thought to consume sulfide generated in underlying sediment. Despite the high abundance of dissolved methane in hydrocarbon seeps, few studies have considered the importance of methanotrophy in mat communities. To assess the importance of methanotrophs in microbial mats from hydrocarbon seeps, an approach involving lipid biomarkers, stable isotopes and enrichment culturing was applied. Microbial mat samples were collected from benthic surfaces at two hydrocarbon seeps located in the Coal Oil Point seep field, offshore from Goleta, California. Both samples display a high abundance of 16:1 fatty acids, including two isomers specific to type I methanotrophic bacteria, 16:1(w8) and 16:1(w6). Depleted values of d 13 C found in 16:1 fatty acids suggests methane assimilation into biomass, whereas three separate investigations of sulfide-oxidizing bacteria yield fractionation factors too small to account for these values. On the basis of these observations and experiments, an isotope mass balance was applied to fatty acids present in the microbial mat samples which indicates methanotrophs contribute up to 46% of total fatty acids. These results implicate methanotrophy as an important function for microbial mats in seep areas, despite the visual appearance of these mats as being composed of giant sulfur bacteria.

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“…Finally, not all sheath‐forming iron‐encrusted Leptothrix morphotypes are necessarily phylogenetic members of the SLG. Sheath formation is widespread and, in combination with iron deposition, found in the GammaproteobacteriaClonothrix fusca, and Crenothrix polyspora (Völker et al ., ; Vigliotta et al ., ). It is not possible to unambiguously assign morphotypes observed in nature to cultured or genetically known species (species candidates resp.…”

Section: Resultsmentioning

confidence: 99%

Isolation ofSphaerotilus-Leptothrixstrains from iron bacteria communities in Tierra del Fuego wetlands

Schmidt

Sánchez

Fretschner

et al. 2014

FEMS Microbiol Ecol

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Sheath-forming iron- and manganese-depositing bacteria belonging to the Sphaerotilus-Leptothrix group (SLG) are widespread in natural and artificial water systems. Known requirements for their growth include the presence of organic substrates and molecular oxygen. High concentrations of reduced iron or manganese, although not necessary for most species, make their growth a noticeable phenomenon. Such microbial communities have been studied mostly in the Northern Hemisphere. Here, we present descriptions of diverse ochre-depositing microbial communities in Tierra del Fuego, Argentina, using a combined approach of microscopical examination, clone library construction and cultivation focused on SLG bacteria. To date, only few SLG type strains are available. The present work increases the number and diversity of cultivated SLG bacteria by obtaining isolates from biofilms and sediment samples of wetlands in Tierra del Fuego. Thirty isolates were selected based on morphological features such as sheath formation and iron/manganese deposition. Five operational taxonomic units (OTUs) were deduced. Sequencing of 16S rRNA genes showed that one OTU is identical to the Leptothrix mobilis Feox-1(T) -sequence while the four remaining OTUs show similarity values related to previously described type strains. Similarity values ranged from 96.5% to 98.8%, indicating possible new species and subspecies.

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Morphology and ultrastructure of Crenothrix polyspora Cohn

Cited by 42 publications

References 17 publications

Phylogenomic Analysis of the Gammaproteobacterial Methanotrophs (Order Methylococcales) Calls for the Reclassification of Members at the Genus and Species Levels

Phylogenomic Analysis of the Gammaproteobacterial Methanotrophs (Order Methylococcales) Calls for the Reclassification of Members at the Genus and Species Levels

Methanotrophic bacteria occupy benthic microbial mats in shallow marine hydrocarbon seeps, Coal Oil Point, California

Isolation ofSphaerotilus-Leptothrixstrains from iron bacteria communities in Tierra del Fuego wetlands

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