Ultrastructure of the cyanobacterium Nostoc muscorum and exploitation of the culture for hydrogen production.

An effect of various physico-chemical parameters on nitrogenase-catalyzed oxygen-free hydrogen production by Nostoc muscorum was demonstrated. More hydrogen was produced in the light than in the dark. Optimum temperature was 40 degrees C Various sugars increased hydrogen production whereas on easily metabolized nitrogen sources it was inhibited. The production was sensitive to salinity and Fe3+, Cu2+, Zn2+ and Ni2+ ions. Ultrastructural study revealed many electron-dense layers outside the cell-wall area that have not been observed earlier.