RT Journal Article SR Electronic(1) A1 King, C. E. A1 King, G. M.YR 2014 T1 Thermomicrobium carboxidum sp. nov., and Thermorudis peleae gen. nov., sp. nov., carbon monoxide-oxidizing bacteria isolated from geothermally heated biofilms JF International Journal of Systematic and Evolutionary Microbiology, VO 64 IS Pt_8 SP 2586 OP 2592 DO https://doi.org/10.1099/ijs.0.060327-0 PB Microbiology Society, SN 1466-5034, AB Two thermophilic, Gram-stain-positive, rod-shaped, non-spore-forming bacteria (strains KI3T and KI4T) were isolated from geothermally heated biofilms growing on a tumulus in the Kilauea Iki pit crater on the flank of Kilauea Volcano (Hawai‘i, USA). Strain KI3T grew over an examined temperature range of 50–70 °C (no growth at 80 °C) and a pH range of 6.0–9.0, with optimum growth at 70 °C and pH 7.0. Strain KI4T grew at temperatures of 55–70 °C and a pH range of 5.8–8.0, with optimum growth at 65 °C and pH 6.7–7.1. The DNA G+C contents of strains KI3T and KI4T were 66.0 and 60.7 mol%, respectively. The major fatty acid for both strains was 12-methyl C18 : 0. Polar lipids in strain KI3T were dominated by glycolipids and phosphatidylinositol, while phosphatidylinositol and phosphoglycolipids dominated in strain KI4T. Strain KI3T oxidized carbon monoxide [6.7±0.8 nmol CO h−1 (mg protein)−1], but strain KI4T did not. 16S rRNA gene sequence analyses determined that the strains belong to the class Thermomicrobia , and that strains KI3T and KI4T are related most closely to Thermomicrobium roseum DSM 5159T (96.5 and 91.1 % similarity, respectively). 16S rRNA gene sequence similarity between strain KI3T and strain KI4T was 91.4 %. Phenotypic features and phylogenetic analyses supported the affiliation of strain KI3T to the genus Thermomicrobium , while results of chemotaxonomic, physiological and biochemical assays differentiated strains KI3T and KI4T from Thermomicrobium roseum . Strain KI3T ( = DSM 27067T = ATCC BAA-2535T) is thus considered to be the type strain of a novel species, for which the name Thermomicrobium carboxidum sp. nov. is proposed. Additionally, the characterization and phylogenetic position of strain KI4T showed that it represents a novel species of a new genus, for which the name Thermorudis peleae gen. nov., sp. nov. is proposed. The type strain of Thermorudis peleae is KI4T ( = DSM 27169T = ATCC BAA-2536T)., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.060327-0