title: Isolation from oil reservoirs of novel thermophilic anaerobes phylogenetically related to Thermoanaerobacter subterraneus: reassignment of T. subterraneus, Thermoanaerobacter yonseiensis, Thermoanaerobacter tengcongensis and Carboxydibrachium pacificum to Caldanaerobacter subterraneus gen. nov., sp. nov., comb. nov. as four novel subspecies.
abstract: Novel thermophilic, anaerobic, Gram-positive, rod-shaped bacteria, strains SL9 and OCA1, were isolated from oilfields in France and Australia, respectively. Both strains, together with Thermoanaerobacter yonseiensis KB-1(T) (=DSM 13777(T)), Thermoanaerobacter tengcongensis MB4(T) (=DSM 15242(T)) and Carboxydibrachium pacificum JM(T) (=DSM 12653(T)), possessed genomic (DNA-DNA hybridization studies) and phylogenetic similarities with Thermoanaerobacter subterraneus SEBR 7858(T) (=DSM 13054(T)), which was isolated recently from an oilfield reservoir in south-west France. Marked phenotypic differences exist between the three oilfield isolates (T. subterraneus, strain OCA1 and strain SL9): they include temperature range for growth and substrates used. Differences were also observed in the DNA G+C contents of all organisms. Similarly to T. subterraneus, strains SL9 and OCA1, and also T. yonseiensis, T. tengcongensis and Carboxydibrachium pacificum, produced acetate and L-alanine as major end products of glucose metabolism [0.8-1.0 mol L-alanine produced (mol glucose consumed)(-1)] and reduced thiosulfate, but not sulfate, to sulfide. Because of these significant metabolic and phylogenetic differences between the oilfield isolates (T. subterraneus, strain OCA1 and strain SL9), T. yonseiensis, T. tengcongensis and Carboxydibrachium pacificum and other Thermoanaerobacter species, it is proposed to reassign them as a novel genus and species, Caldanaerobacter subterraneus gen. nov., sp. nov., comb. nov., with the creation of four novel subspecies, Caldanaerobacter subterraneus subsp. subterraneus subsp. nov., comb. nov., Caldanaerobacter subterraneus subsp. yonseiensis subsp. nov., comb. nov., Caldanaerobacter subterraneus subsp. tengcongensis subsp. nov., comb. nov. and Caldanaerobacter subterraneus subsp. pacificus subsp. nov., comb. nov.
authors.affiliation: IRD, UR101 Extrêmophiles, IFR-BAIM, Universités de Provence et de la Méditerranée, ESIL case 925, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Fardeau
authors.affiliation: IRD, UR101 Extrêmophiles, IFR-BAIM, Universités de Provence et de la Méditerranée, ESIL case 925, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Monica Bonilla
authors.initials: MB
authors.lastname: Salinas
authors.affiliation: UMR CNRS 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, 29680 Plouzané, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: L'Haridon
authors.affiliation: UMR CNRS 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, 29680 Plouzané, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Jeanthon
authors.affiliation: IRD, UR101 Extrêmophiles, IFR-BAIM, Universités de Provence et de la Méditerranée, ESIL case 925, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Verhé
authors.affiliation: IRD, UR101 Extrêmophiles, IFR-BAIM, Universités de Provence et de la Méditerranée, ESIL case 925, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Cayol
authors.affiliation: School of Biomolecular and Biomedical Sciences, Griffith University, Brisbane, Australia.
authors.forename: Bharat K C
authors.initials: BKC
authors.lastname: Patel
authors.affiliation: IRD, UR101 Extrêmophiles, IFR-BAIM, Universités de Provence et de la Méditerranée, ESIL case 925, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Garcia
authors.affiliation: IRD, UR101 Extrêmophiles, IFR-BAIM, Universités de Provence et de la Méditerranée, ESIL case 925, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Ollivier
mesh_terms: D000693:Anaerobiosis; D001315:Australia; D001421:Bacteria, Anaerobic / Q000145:classification* / Q000302:isolation & purification; D001482:Base Composition; D001483:Base Sequence; D003013:Clostridium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D017931:DNA Primers; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005579:Fossil Fuels / Q000382:microbiology*; D005602:France; D008969:Molecular Sequence Data; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005579:Fossil Fuels; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S