title: A new chemolithoautotrophic arsenite-oxidizing bacterium isolated from a gold mine: phylogenetic, physiological, and preliminary biochemical studies.
abstract: A previously unknown chemolithoautotrophic arsenite-oxidizing bacterium has been isolated from a gold mine in the Northern Territory of Australia. The organism, designated NT-26, was found to be a gram-negative motile rod with two subterminal flagella. In a minimal medium containing only arsenite as the electron donor (5 mM), oxygen as the electron acceptor, and carbon dioxide-bicarbonate as the carbon source, the doubling time for chemolithoautotrophic growth was 7.6 h. Arsenite oxidation was found to be catalyzed by a periplasmic arsenite oxidase (optimum pH, 5.5). Based upon 16S rDNA phylogenetic sequence analysis, NT-26 belongs to the Agrobacterium/Rhizobium branch of the alpha-Proteobacteria and may represent a new species. This recently discovered organism is the most rapidly growing chemolithoautotrophic arsenite oxidizer known.
authors.affiliation: Department of Microbiology, La Trobe University, Bundoora, Victoria 3083, Australia.
authors.forename: J M
authors.initials: JM
authors.lastname: Santini
authors.forename: L I
authors.initials: LI
authors.lastname: Sly
authors.forename: R D
authors.initials: RD
authors.lastname: Schnagl
authors.forename: J M
authors.initials: JM
authors.lastname: Macy
mesh_terms: D020561:Alphaproteobacteria / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology; D018053:Arsenites / Q000378:metabolism*; D003470:Culture Media; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D006046:Gold; D006091:Gram-Negative Chemolithotrophic Bacteria / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology; D008906:Mining; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D018053:Arsenites; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D006046:Gold; C015001:arsenite