Treatment with moderate concentrations of NaHSO3 enhances photobiological H2 production in the cyanobacterium Anabaena sp strain PCC 7120

In cyanobacteria treatment with low concentrations of NaHSO3 can enhance photosynthetic efficiency whereas NaHSO3 in high amounts often inhibits cell growth and photo synthesis may even cause death In the present study our results showed that treatment with moderate concentrations of NaHSO3 considerably improved the yield of photobiological H-2 production in the filamentous N-2 fixing cyanobacterium Anabaena sp strain PCC 7120 Under steady state conditions the accumulated H-2 levels in cells treated with 1 mM NaHSO3 were approximately 10 times higher than that in untreated cells Such improvement occurred in heterocysts and was most likely caused by increases in the expression and activity of nitrogenase The effects of treatment with low moderate and high concentrations of NaHSO3 in cyanobacteria were proposed on the basis of the results obtained in the present study and from previous knowledge (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved