title: Isolation and characterisation of mineral-oxidising "Acidibacillus" spp. from mine sites and geothermal environments in different global locations.
abstract: Eight strains of acidophilic bacteria, isolated from mine-impacted and geothermal sites from different parts of the world, were shown to form a distinct clade (proposed genus "Acidibacillus") within the phylum Firmicutes, well separated from the acidophilic genera Sulfobacillus and Alicyclobacillus. Two of the strains (both isolated from sites in Yellowstone National Park, USA) were moderate thermophiles that oxidised both ferrous iron and elemental sulphur, while the other six were mesophiles that also oxidised ferrous iron, but not sulphur. All eight isolates reduced ferric iron to varying degrees. The two groups shared <95% similarity of their 16S rRNA genes and were therefore considered to be distinct species: "Acidibacillus sulfuroxidans" (moderately thermophilic isolates) and "Acidibacillus ferrooxidans" (mesophilic isolates). Both species were obligate heterotrophs; none of the eight strains grew in the absence of organic carbon. "Acidibacillus" spp. were generally highly tolerant of elevated concentrations of cationic transition metals, though "A. sulfuroxidans" strains were more sensitive to some (e.g. nickel and zinc) than those of "A. ferrooxidans". Initial annotation of the genomes of two strains of "A. ferrooxidans" revealed the presence of genes (cbbL) involved in the RuBisCO pathway for CO2 assimilation and iron oxidation (rus), though with relatively low sequence identities.
authors.affiliation: College of Natural Sciences, Bangor University, UK. Electronic address: bsp40e@bangor.ac.uk.
authors.forename: Roseanne
authors.initials: R
authors.lastname: Holanda
authors.affiliation: Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover, Germany. Electronic address: Sabrina.Hedrich@bgr.de.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Hedrich
authors.affiliation: Vale Institute of Technology, Belém, Pará, Brazil; Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Lientur 1457, Concepción 4080871, Chile. Electronic address: inancucheo@gmail.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Ňancucheo
authors.affiliation: Vale Institute of Technology, Belém, Pará, Brazil. Electronic address: guilherme.oliviera@itv.org.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Oliveira
authors.affiliation: College of Natural Sciences, Bangor University, UK. Electronic address: b.m.grail@bangor.ac.uk.
authors.forename: Barry M
authors.initials: BM
authors.lastname: Grail
authors.affiliation: College of Natural Sciences, Bangor University, UK. Electronic address: d.b.johnson@bangor.ac.uk.
authors.forename: D Barrie
authors.initials: DB
authors.lastname: Johnson
mesh_terms: D056449:Bacillales / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004783:Environmental Microbiology; D005290:Ferric Compounds / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D052836:Heterotrophic Processes; D008903:Minerals / Q000378:metabolism*; D009930:Organic Chemicals / Q000378:metabolism; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005290:Ferric Compounds; D005296:Ferrous Compounds; D008903:Minerals; D009930:Organic Chemicals; D012336:RNA, Ribosomal, 16S; D013455:Sulfur; D002244:Carbon
keywords: Acidibacillus; Acidophiles; Chemolitho-heterotrophs; Iron oxidation; Novel species