Enhanced photo-biological H2 production by two synchronously grown N2-fixing cyano-bacterial strains, MAL-CB031 and Miami BG 043511

We investigated photo-biological H2 production by two N2-fixing marine cyano-bacterial strains, MAL-CB031 and Miami BG 043511. Optimal temperature and salinity for the maximum growth were quite lower in the temperate strain MAL-CB031 than those in the subtropical stain Miami BG 043511. Both strains grow normally even in seawater-based modified f/2-N media (without any added inorganic nitrogen) for extended periods, showing up their N2-fixing ability. The first detection of the photo-biologically produced H2 was made at 24 h and 36 h after the onset of the incubation in N2-fixing and synchronized cells (NF-SN cells) and non-N2-fixing and un-synchronized cells (xNF-xSN cells), respectively. Maximal accumulation of H2 in the 25-ml micro-Fernbach flasks were 1.18 and 0.70 ml/5 ml-suspension in MAL-CB031 and Miami BG 043511, respectively. Present study would be recorded as the first challenge for the photo-biological H2 production by Korean marine cyano-bacterial strains. (authors)