The photobiocatalytic system: Inorganic semiconductors coupled to bacterial cells

Considering the evolutionary pathways of solar energy conversion, we suggested that some mineral components of the earth's crust might have been capable of electron phototransfer coupled to the metabolic chains of primary heterotrophic cells. We observed a peculiar type of this process when light‐exposed particles of titanium dioxide or some other minerals initiated an electron transfer from organic electron donors to Clostridium butyricum bacterial cells, with hydrogen being evolved as a result of intra‐ and extracellular activity of hydrogenase. The coupling of mineral photocatalysts to bacterial cells may be regarded as a way to create a new type of photobiocatalytic system.