title: Contribution of intracellular negative ion capacity to Donnan effect across the membrane in alkaliphilic Bacillus spp.
abstract: To elucidate the energy production mechanism of alkaliphiles, the relationship between the H(+) extrusion rate by the respiratory chain and the corresponding ATP synthesis rate was determined in the facultative alkaliphile Bacillus cohnii YN-2000 and compared with those in the obligate alkaliphile Bacillus clarkii DSM 8720(T) and the neutralophile Bacillus subtilis IAM 1026. Under high aeration condition, much higher ATP synthesis rates and larger Δψ in the alkaliphilic Bacillus spp. grown at pH 10 than those in the neutralophilic B. subtilis grown at pH 7 were observed. This high ATP productivity could be attributed to the larger Δψ in alkaliphiles than in B. subtilis because the H(+) extrusion rate in alkaliphiles cannot account for the high ATP productivity. However, the large Δψ in the alkaliphiles could not be explained only by the H(+) translocation rate in the respiratory chain in alkaliphiles. There is a possibility that the Donnan effect across the membrane has the potential to contribute to the large Δψ. To estimate the contribution of the Donnan effect to the large Δψ in alkaliphilic Bacillus spp. grown at pH 10, intracellular negative ion capacity was examined. The intracellular negative ion capacities in alkaliphiles grown at pH 10 under high aeration condition corresponding to their intracellular pH (pH 8.1) were much higher than those in alkaliphiles grown under low aeration condition. A proportional relationship is revealed between the negative ion capacity and Δψ in alkaliphiles grown under different aeration conditions. This relationship strongly suggests that the intracellular negative ion capacity contributes to the formation of Δψ through the Donnan effect in alkaliphilic Bacillus spp. grown at pH 10.
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido, 060-8589, Japan.|Bioproduction Research Insitute, National Institute of Advanced Science and Technology, 2-17-2-1, Tsukisamu-Higashi, Toyohira-ku, Sapporo, Hokkaido, 062-8517, Japan.
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Goto
authors.affiliation: Department of Bioscience and Technology, School of Biological Science and Engineering, Tokai University, Minaminosawa, Minami-ku, Sapporo, Hokkaido, 005-8601, Japan.
authors.forename: Toshinao
authors.initials: T
authors.lastname: Hirabayashi
authors.affiliation: Department of Bioscience and Technology, School of Biological Science and Engineering, Tokai University, Minaminosawa, Minami-ku, Sapporo, Hokkaido, 005-8601, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Morimoto
authors.affiliation: Department of Marine Bioresources Chemistry, Faculty of Fisheries, Hokkaido University, 3-1-1, Minoto-cho, Hakodate, Hokkaido, 041-0821, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yamazaki
authors.affiliation: Department of Marine Bioresources Chemistry, Faculty of Fisheries, Hokkaido University, 3-1-1, Minoto-cho, Hakodate, Hokkaido, 041-0821, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Inoue
authors.affiliation: Department of Bioscience and Technology, School of Biological Science and Engineering, Tokai University, Minaminosawa, Minami-ku, Sapporo, Hokkaido, 005-8601, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Matsuyama
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido, 060-8589, Japan. i.yumoto@aist.go.jp.|Bioproduction Research Insitute, National Institute of Advanced Science and Technology, 2-17-2-1, Tsukisamu-Higashi, Toyohira-ku, Sapporo, Hokkaido, 062-8517, Japan. i.yumoto@aist.go.jp.
authors.forename: Isao
authors.initials: I
authors.lastname: Yumoto
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D001407:Bacillus / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D004579:Electron Transport / Q000502:physiology; D008564:Membrane Potentials / Q000502:physiology*; D018892:Proton-Motive Force / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D000255:Adenosine Triphosphate
keywords: Alkaliphile; Donnan effect; Negative ion capacity; Δψ