抄録
The structural and functional changes in Photosystem (PS)II caused by the transfer of Lyngbya cells from growing conditions to hydrogen-producing conditions were studied. By sodium dodecy sulfate (SDS)-polyacrylamide analyses assisted by immune-detection, we demonstrated the degradation of PSII proteins under hydrogen-producing conditions, which first gives rise to the loss of oxygen evolution followed by the loss of the reaction center in PSII. It was also found by fluorescence analyses that these changes are preceded by functional dissociation of PSI from PSII as expressed by the loss of excitation energy transfer between the two photosystems. These results are sustained by the action spectrum for hydrogen production, the major contribution of PSI as the photoreceptor for lightdependent hydrogen production by Lyngbya cells.