PHOTOINHIBITION AND CHLOROPHYLL PHOTOBLEACHING IN IMMOBILIZED THYLAKOID MEMBRANES

Thylakoid membranes can be immobilized to enhance their stability in photoelectrochemical cells exposed to strong continuous illumination. This paper studies the effect of such immobilization in a glutaraldehyde-albumin crosslinked matrix on the rates of photoinhibition of electron transfer and chlorophyll photobleaching. The immobilization matrix constituted an efficient oxygen diffusion barrier that prevents chlorophyll photobleaching to a great extent. The photoprotection was less efficient against photoinhibition as seen by monitoring oxygen evolution after given periods of preillumination in the cell of a photoacoustic spectrophotometer. The results also indicated that light dispersion by the immobilization matrix was not a critical factor for photoprotection.