title: Alkaline iron(III) reduction by a novel alkaliphilic, halotolerant, Bacillus sp. isolated from salt flat sediments of Soap Lake.
abstract: A halotolerant, alkaliphilic dissimilatory Fe(III)-reducing bacterium, strain SFB, was isolated from salt flat sediments collected from Soap Lake, WA. 16S ribosomal ribonucleic acid gene sequence analysis identified strain SFB as a novel Bacillus sp. most similar to Bacillus agaradhaerens (96.7% similarity). Strain SFB, a fermentative, facultative anaerobe, fermented various hexoses including glucose and fructose. The fructose fermentation products were lactate, acetate, and formate. Under fructose-fermenting conditions in a medium amended with Fe(III), Fe(II) accumulated concomitant with a stoichiometric decrease in lactate and an increase in acetate and CO(2). Strain SFB was also capable of respiratory Fe(III) reduction with some unidentified component(s) of Luria broth as an electron donor. In addition to Fe(III), strain SFB could also utilize nitrate, fumarate, or O(2) as alternative electron acceptors. Optimum growth was observed at 30 degrees C and pH 9. Although the optimal salinity for growth was 0%, strain SFB could grow in a medium with up to 15% NaCl by mass. These studies describe a novel alkaliphilic, halotolerant organism capable of dissimilatory Fe(III) reduction under extreme conditions and demonstrate that Bacillus species can contribute to the microbial reduction of Fe(III) in environments at elevated pH and salinity, such as soda lakes.
authors.affiliation: University of California, Berkeley, CA 94720, USA.
authors.forename: Jarrod
authors.initials: J
authors.lastname: Pollock
authors.forename: Karrie A
authors.initials: KA
authors.lastname: Weber
authors.forename: Joe
authors.initials: J
authors.lastname: Lack
authors.forename: Laurie A
authors.initials: LA
authors.lastname: Achenbach
authors.forename: Melanie R
authors.initials: MR
authors.lastname: Mormile
authors.forename: John D
authors.initials: JD
authors.lastname: Coates
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000468:Alkalies; D001407:Bacillus / Q000145:classification* / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal; D005290:Ferric Compounds / Q000378:metabolism*; D005618:Fresh Water / Q000382:microbiology; D019015:Geologic Sediments / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D000085:Acetates; D000468:Alkalies; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005290:Ferric Compounds; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D007501:Iron