FIG. 7.

Mass spectrometric measurements of H₂, O₂, and CO₂ exchange in the Synechocystis ndhB mutant M55 in darkness and during a 25-min illumination period. Cells were adapted for 1 h under anaerobiosis in the dark in a closed vessel connected to a mass spectrometer, and the concentrations of H₂, O₂, and CO₂ in the medium were continuously monitored. (A) Control, (B) with 10 mM glucose, and (C) with 10 mM glucose plus glucose oxidase plus catalase. Conditions were the same as for Fig. 6 except for the duration of the illumination period. Dark periods are represented on the x axis by black bars, and the light period is represented by a white bar.