Abstract

Recently many enzymes, microbial whole cells and organelles, immobilized by various methods, were applied in many fields (1). The important problem of biological energy conversion has emphasized the use of immobilized photosynthetic systems such as chloroplast membranes (thylakoids) to produce hydrogen and ATP regeneration (2-4). After immobilization by various methods (4) large variations in the functional stability were observed in the activity yield of lettuce thylakoids. Since immobilized thylakoids in different environments (albumin, carrageenan, alginate, polyurethan) appear as solid and amorphous particles, photoacoustic spectroscopy (PAS) (already performed by one of us (5) on immobilized hemoglobin particles) is expected to provide a valuable method to characterize the processes of energy conversion. Furthermore, Cahen and coworkers (6-8) have extensively applied PAS to fundamental photosynthesis studies.

© 1981 Optical Society of America