THE MOLECULAR-HYDROGEN PRODUCTION BY CELLS OF CYANOBACTERIA NOSTOC-MUSCORUM IMMOBILIZED BY TITANIUM-DIOXIDE

The cells of cyanobacteria Nostoc muscorum immobilized by TiO2 were fo und to produce H-2 under reducing conditions mostly in darkness, while the free cells demonstrated this activity mainly in light. The rate o f H-2 production under reducing conditions was by three orders of magn itude higher in the immobilized cells than in the free cells. It was c oncluded that the stimulation of H-2 production during cell immobiliza tion occurred as a result of the hydrogenase activation because the ni trogenase activity was similar in the free and immobilized cells. The activation of H-2 production was related to the specific changes in bo th morphology and spectral properties of the immobilized cells.