title: Caldicellulosiruptor obsidiansis sp. nov., an anaerobic, extremely thermophilic, cellulolytic bacterium isolated from Obsidian Pool, Yellowstone National Park.
abstract: A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47(T), was isolated from Obsidian Pool, Yellowstone National Park, WY. The isolate was a nonmotile, non-spore-forming, Gram-positive rod approximately 2 microm long by 0.2 microm wide and grew at temperatures between 55 and 85 degrees C, with the optimum at 78 degrees C. The pH range for growth was 6.0 to 8.0, with values of near 7.0 being optimal. Growth on cellobiose produced the fastest specific growth rate at 0.75 h(-1). The organism also displayed fermentative growth on glucose, maltose, arabinose, fructose, starch, lactose, mannose, sucrose, galactose, xylose, arabinogalactan, Avicel, xylan, filter paper, processed cardboard, pectin, dilute acid-pretreated switchgrass, and Populus. OB47(T) was unable to grow on mannitol, fucose, lignin, Gelrite, acetate, glycerol, ribose, sorbitol, carboxymethylcellulose, and casein. Yeast extract stimulated growth, and thiosulfate, sulfate, nitrate, and sulfur were not reduced. Fermentation end products were mainly acetate, H2, and CO2, although lactate and ethanol were produced in 5-liter batch fermentations. The G+C content of the DNA was 35 mol%, and sequence analysis of the small subunit rRNA gene placed OB47(T) within the genus Caldicellulosiruptor. Based on its phylogenetic and phenotypic properties, the isolate is proposed to be designated Caldicellulosiruptor obsidiansis sp. nov. and OB47 is the type strain (ATCC BAA-2073).
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, P.O. Box 2008 MS6038, Oak Ridge, TN 37831, USA.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Hamilton-Brehm
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Mosher
authors.forename: Tatiana
authors.initials: T
authors.lastname: Vishnivetskaya
authors.forename: Mircea
authors.initials: M
authors.lastname: Podar
authors.forename: Sue
authors.initials: S
authors.lastname: Carroll
authors.forename: Steve
authors.initials: S
authors.lastname: Allman
authors.forename: Tommy J
authors.initials: TJ
authors.lastname: Phelps
authors.forename: Martin
authors.initials: M
authors.lastname: Keller
authors.forename: James G
authors.initials: JG
authors.lastname: Elkins
mesh_terms: D001421:Bacteria, Anaerobic / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001482:Base Composition; D001483:Base Sequence; D002475:Cellobiose / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005285:Fermentation; D005798:Genes, Bacterial; D006358:Hot Temperature; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014871:Water Microbiology; D014959:Wyoming
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D002475:Cellobiose