title: Response of the microaerophilic Bifidobacterium species, B. boum and B. thermophilum, to oxygen.
abstract: We investigated the effects of O2 on Bifidobacterium species using liquid shaking cultures under various O2 concentrations. Although most of the Bifidobacterium species we selected showed O2 sensitivity, two species, B. boum and B. thermophilum, demonstrated microaerophilic profiles. The growth of B. bifidum and B. longum was inhibited under high-O2 conditions accompanied by the accumulation of H2O2 in the medium, and growth was restored by adding catalase to the medium. B. boum and B. thermophilum grew well even under 20% O2 conditions without H2O2 accumulation, and growth was stimulated compared to anoxic growth. H2O-forming NADH oxidase activities were detected dominantly in cell extracts of B. boum and B. thermophilum under acidic reaction conditions (pH 5.0 to 6.0).
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Setagaya-ku, Tokyo 156-8502, Japan. kawashin@nodai.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawasaki
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Mimura
authors.forename: Takumi
authors.initials: T
authors.lastname: Satoh
authors.forename: Kouji
authors.initials: K
authors.lastname: Takeda
authors.forename: Youichi
authors.initials: Y
authors.lastname: Niimura
mesh_terms: D001644:Bifidobacterium / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*
chemical_list: D009097:Multienzyme Complexes; D006861:Hydrogen Peroxide; D002374:Catalase; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D010100:Oxygen