title: Bacillus cereus electron transport and proton motive force during aerotaxis.
abstract: Aerotaxis (migration towards oxygen) of Bacillus cereus M63, a motile strain, was inhibited by potassium cyanide and 2-heptyl-4-hydroxyquinoline N-oxide, indicating a requirement for both the terminal oxidase (cytochrome aa3) and the cytochrome b segment of the electron transport system. The concentration of oxygen that gave a half-maximal aerotactic response (K0.5) was 0.31 microM, which was similar to the Km for respiration (0.80 microM). The proton motive force increased from -135 to -177 mV when anaerobic cells were aerated, and it is proposed that the signal for aerotaxis is the increase in proton motive force that results from increased respiration. A strain of B. cereus T initially used in this study was immotile, grew as long chains of cells, and was deficient in autolytic enzyme. B. cereus M63 is a spontaneous derivative of B. cereus T that has normal motility.
mesh_terms: D001409:Bacillus cereus / Q000378:metabolism / Q000502:physiology*; D002465:Cell Movement; D002633:Chemotaxis; D004579:Electron Transport; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010100:Oxygen; D010101:Oxygen Consumption
chemical_list: D010100:Oxygen