Miyamoto et al. (1979) reported that H2
production was stimulated by 50% in the presence of DCMU under
nitrogen limiting conditions. However, there have been only very
limited studies on the inhibition of competing pathways for H2
production in N2-fixing cyanobacteria. Moreover, very little is
known about the relationship of photosynthesis, respiration and
H2 metabolism in heterocysts and vegetative cells.