title: Ignicoccus gen. nov., a novel genus of hyperthermophilic, chemolithoautotrophic Archaea, represented by two new species, Ignicoccus islandicus sp nov and Ignicoccus pacificus sp nov. and Ignicoccus pacificus sp. nov.
abstract: Two species of novel, chemolithoautotrophic, sulfidogenic micro-organisms were isolated from submarine hydrothermal systems in the Atlantic (at the Kolbeinsey Ridge north of Iceland) and in the Pacific (at 9 degrees N, 104 degrees W). The coccoid cells grew within a temperature range of 70-98 degrees C (optimum around 90 degrees C). They gained energy by reduction of elemental sulfur using molecular hydrogen as the electron donor. 165 rDNA-based sequence comparisons revealed that the organisms are members of the crenarchaeal branch of the Archaea. They represent a new, deeply branching lineage within the family of the Desulfurococcaceae. In DNA-DNA hybridization experiments both strains exhibited low levels of hybridization to each other and to further representatives of this family. Therefore, they represent a new genus, for which the name Ignicoccus gen. nov. is proposed. At present it consists of two new species, Ignicoccus islandicus sp. nov. (type strain is Kol8T = DSM 13165T = ATCC 700957T) and Ignicoccus pacificus sp. nov. (type strain is LPC33T = DSM 13166T = ATCC 700958T).
authors.forename: H
authors.initials: H
authors.lastname: Huber
authors.forename: S
authors.initials: S
authors.lastname: Burggraf
authors.forename: T
authors.initials: T
authors.lastname: Mayer
authors.forename: I
authors.initials: I
authors.lastname: Wyschkony
authors.forename: R
authors.initials: R
authors.lastname: Rachel
authors.forename: K O
authors.initials: KO
authors.lastname: Stetter
mesh_terms: D001482:Base Composition; D003470:Culture Media; D004275:DNA, Ribosomal / Q000032:analysis; D019620:Desulfurococcaceae / Q000145:classification* / Q000235:genetics / Q000254:growth & development*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000378:metabolism*; D013696:Temperature
chemical_list: D003470:Culture Media; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D013455:Sulfur