title: Biology of archaea from a novel family Cuniculiplasmataceae (Thermoplasmata) ubiquitous in hyperacidic environments.
abstract: The order Thermoplasmatales (Euryarchaeota) is represented by the most acidophilic organisms known so far that are poorly amenable to cultivation. Earlier culture-independent studies in Iron Mountain (California) pointed at an abundant archaeal group, dubbed 'G-plasma'. We examined the genomes and physiology of two cultured representatives of a Family Cuniculiplasmataceae, recently isolated from acidic (pH 1-1.5) sites in Spain and UK that are 16S rRNA gene sequence-identical with 'G-plasma'. Organisms had largest genomes among Thermoplasmatales (1.87-1.94 Mbp), that shared 98.7-98.8% average nucleotide identities between themselves and 'G-plasma' and exhibited a high genome conservation even within their genomic islands, despite their remote geographical localisations. Facultatively anaerobic heterotrophs, they possess an ancestral form of A-type terminal oxygen reductase from a distinct parental clade. The lack of complete pathways for biosynthesis of histidine, valine, leucine, isoleucine, lysine and proline pre-determines the reliance on external sources of amino acids and hence the lifestyle of these organisms as scavengers of proteinaceous compounds from surrounding microbial community members. In contrast to earlier metagenomics-based assumptions, isolates were S-layer-deficient, non-motile, non-methylotrophic and devoid of iron-oxidation despite the abundance of methylotrophy substrates and ferrous iron in situ, which underlines the essentiality of experimental validation of bioinformatic predictions.
authors.affiliation: School of Biological Sciences, Bangor University, Deiniol Rd, Bangor, LL57 2UW, UK.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Golyshina
authors.affiliation: Winogradsky Institute of Microbiology, Research Center for Biotechnology Russian Academy of Sciences, Prospect 60-Letiya Oktyabrya 7/2, Moscow, 117312, Russia.
authors.forename: Ilya V
authors.initials: IV
authors.lastname: Kublanov
authors.affiliation: School of Biological Sciences, Bangor University, Deiniol Rd, Bangor, LL57 2UW, UK.
authors.forename: Hai
authors.initials: H
authors.lastname: Tran
authors.affiliation: Immanuel Kant Baltic Federal University, 236040 Kaliningrad, Russia.
authors.forename: Alexei A
authors.initials: AA
authors.lastname: Korzhenkov
authors.affiliation: Central Unit of Microscopy, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, Braunschweig, 38124, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Lünsdorf
authors.affiliation: Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, Jena, 07745, Germany.
authors.forename: Taras Y
authors.initials: TY
authors.lastname: Nechitaylo
authors.affiliation: Winogradsky Institute of Microbiology, Research Center for Biotechnology Russian Academy of Sciences, Prospect 60-Letiya Oktyabrya 7/2, Moscow, 117312, Russia.
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Gavrilov
authors.affiliation: Immanuel Kant Baltic Federal University, 236040 Kaliningrad, Russia.
authors.forename: Stepan V
authors.initials: SV
authors.lastname: Toshchakov
authors.affiliation: School of Biological Sciences, Bangor University, Deiniol Rd, Bangor, LL57 2UW, UK.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Golyshin
mesh_terms: D000143:Acids / Q000737:chemistry*; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism; D002140:California; D017753:Ecosystem; D019605:Euryarchaeota / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D020745:Genome, Archaeal / Q000235:genetics*; D023281:Genomics / Q000379:methods; D005843:Geography; D006863:Hydrogen-Ion Concentration; D008854:Microscopy, Electron; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013030:Spain; D019603:Thermoplasmales / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D006113:United Kingdom
chemical_list: D000143:Acids; D019843:Archaeal Proteins; D012336:RNA, Ribosomal, 16S