title: Anaerobic respiration using Fe(3+), S(0), and H(2) in the chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans.
abstract: The chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans has been known as an aerobe that respires on iron and sulfur. Here we show that the bacterium could chemolithoautotrophically grow not only on H(2)/O(2) under aerobic conditions but also on H(2)/Fe(3+), H(2)/S(0), or S(0)/Fe(3+) under anaerobic conditions. Anaerobic respiration using Fe(3+) or S(0) as an electron acceptor and H(2) or S(0) as an electron donor serves as a primary energy source of the bacterium. Anaerobic respiration based on reduction of Fe(3+) induced the bacterium to synthesize significant amounts of a c-type cytochrome that was purified as an acid-stable and soluble 28-kDa monomer. The purified cytochrome in the oxidized form was reduced in the presence of the crude extract, and the reduced cytochrome was reoxidized by Fe(3+). Respiration based on reduction of Fe(3+) coupled to oxidation of a c-type cytochrome may be involved in the primary mechanism of energy production in the bacterium on anaerobic iron respiration.
authors.affiliation: Department of Bio-Science, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-City Chiba 270-1194, Japan. ohmura@criepi.denken.or.jp
authors.forename: Naoya
authors.initials: N
authors.lastname: Ohmura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sasaki
authors.forename: Norio
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Saiki
mesh_terms: D000693:Anaerobiosis; D020563:Gammaproteobacteria / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D013455:Sulfur / Q000378:metabolism*
chemical_list: D009243:NAD; D013455:Sulfur; D006859:Hydrogen; D007501:Iron