Photosynthetic Bacterial Hydrogen Production with Fermentation Products of Cyanobacterium Spirulina platensis

Abstract

The cyanobacterium Spirulina platensis accumulates glycogen photoautotrophically in a nitrogen-deficient medium. Under anaerobic conditions in the dark, the glycogen degrades into org. compds. As mol. hydrogen also evolves in this process, hydrogenase participation is suggested in this metab. We investigated the several conditions necessary for the evolution of hydrogen and prodn. of org. compds. The effects of cell concn., initial pH, and concn. of the buffer were detd. These fermn. products were then converted into mol. hydrogen by using the photosynthetic bacterium Rhodobacter sphaeroides RV with light energy. The compn. of the evolved gas was mainly hydrogen and carbon dioxide. This photosynthetic bacterial prodn. of hydrogen was caused by a nitrogenase-dependent mechanism. Combining this system with photosynthesis of cyanobacteria resulted in the prodn. of hydrogen by splitting water. [on SciFinder(R)]