Photobiological hydrogen production by Korean N2-fixing unicellular cyanobacterial strains

Photobiological hydrogen production by Korean N₂-fixing unicellular cyanobacterial strains

Jong-Woo Park, Wonho Yih

Department of Oceanography, Kunsan National University  Kunsan, 573-701, Republic of Korea

Photobiological hydrogen production by the marine cyanobacteria is beneficial for both clean environment and renewable energy supply. Hydrogen production by N₂-fixing cyanobacteria has long been studied since 1940s.  Excellent strains for high H₂ production, however, are still to be pursued further to meet the future market standard. Using two Korean nitrogen-fixing unicellular cyanobacterial strains(Cyanothece sp. KNU CB MAL-031 and an unidentified cyanobacterium KNU CB MAL-058) we tested to find out the optimum cell concentrations for maximal H₂ production in each of them. H₂ production was measured in experimental bottles with different cell concentrations ranging from one to seven-teen billion cells ml^-1 of the two Korean strains and another comparative strain, Synechococcus sp. Miami BG043511. The upper limit of cell concentrations for optimum H₂ production was 15 billions cells ml^-1.  Average hydrogen production by Cyanothece sp. KNU CB MAL-031 was not less than that by Synechococcus sp. Miami BG043511 at all the tested cell concentrations.  The test strain KNU CB MAL-058 exhibited larger amount of  H₂ production than Synechococcus sp. Miami BG043511 at the range of 5-10 billions cells ml^-1.  Present result suggests that isolation of novel cyanobacterial strains for photobiological H₂ production for future energy supply needs further thorough works.