Hydrogen photoproduction by the synchronously grown marine unicellular cyanobacterium Synechococcus sp. Miami BG 043511 under extremely high oxygen concentration

  • Yih, Won-Ho (School of Marine and Atmospheric Science, University of Miami) ;
  • Takeyama, Haruko (School of Marine and Atmospheric Science, University of Miami) ;
  • Mitsui, Akira (School of Marine and Atmospheric Science, University of Miami)
  • Published : 1996.03.30

Abstract

The effect of exogenous oxygen on hydrogen photoproduction was examined in the synchronously grown cells of marine Synechococcus sp. Miami BG 043511 under conditions of high cell density (0.6-0.8 mg chl-${\alpha}$ $ml^{-1}$) and high light intensity (1000 ${\mu}$E $m^{-2}$ $s^{-1}$). Hydrogen evolution after 20-h incubation did not decline under the initial oxygen concentrations up to 20%, but declined by half under 34% oxygen. 50% and 100% oxygen gas phase did not completely inhibit the hydrogen photoproduction during 40-h incubations. After 2-day pretreatment under 100% exogenous oxygen the hydrogen photoproduction capabilities were not irreversibly inhibited, which was demonstrated in the subsequent 9-day incubation under initial 0, 50 and even under 100% oxygen gas phase. This strain could be useful for developing a hydrogen photoproduction system under atmospheric oxygen concentration.

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