title: Carboxydothermus siderophilus sp. nov., a thermophilic, hydrogenogenic, carboxydotrophic, dissimilatory Fe(III)-reducing bacterium from a Kamchatka hot spring.
abstract: A novel anaerobic, thermophilic, Fe(III)-reducing, CO-utilizing bacterium, strain 1315(T), was isolated from a hot spring of Geyser Valley on the Kamchatka Peninsula. Cells of the new isolate were Gram-positive, short rods. Growth was observed at 52-70 degrees C, with an optimum at 65 degrees C, and at pH 5.5-8.5, with an optimum at pH 6.5-7.2. In the presence of Fe(III) or 9,10-anthraquinone 2,6-disulfonate (AQDS), the bacterium was capable of growth with CO and yeast extract (0.2 g l(-1)); during growth under these conditions, strain 1315(T) produced H(2) and CO(2) and Fe(II) or AQDSH(2), respectively. Strain 1315(T) also grew by oxidation of yeast extract, glucose, xylose or lactate under a N(2) atmosphere, reducing Fe(III) or AQDS. Yeast extract (0.2 g l(-1)) was required for growth. Isolate 1315(T) grew exclusively with Fe(III) or AQDS as an electron acceptor. The generation time under optimal conditions with CO as growth substrate was 9.3 h. The G+C content of the DNA was 41.5+/-0.5 mol%. 16S rRNA gene sequence analysis placed the organism in the genus Carboxydothermus (97.8 % similarity with the closest relative). On the basis of physiological features and phylogenetic analysis, it is proposed that strain 1315(T) should be assigned to a novel species, Carboxydothermus siderophilus sp. nov., with the type strain 1315(T) (=VKPM 9905B(T) =VKM B-2474(T) =DSM 21278(T)).
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60 Let Oktyabrya 7/2, 117312 Moscow, Russia. slepysh@gmail.com
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Slepova
authors.forename: Tatyana G
authors.initials: TG
authors.lastname: Sokolova
authors.forename: Tatyana V
authors.initials: TV
authors.lastname: Kolganova
authors.forename: Tatyana P
authors.initials: TP
authors.lastname: Tourova
authors.forename: Elizaveta A
authors.initials: EA
authors.lastname: Bonch-Osmolovskaya
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism*; D005290:Ferric Compounds / Q000737:chemistry; D016988:Gram-Positive Asporogenous Rods, Irregular / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D045482:Hot Springs / Q000382:microbiology*; D006358:Hot Temperature; D006859:Hydrogen / Q000378:metabolism*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013045:Species Specificity
chemical_list: D005290:Ferric Compounds; D012336:RNA, Ribosomal, 16S; D002245:Carbon Dioxide; C000499:ferric oxide; D006859:Hydrogen