TABLE 1.

Examples of published rates of cyanobacterial H2 formation

CyanobacteriumEnzymeConditionH2 formation rate (μmol/mg chlorophyll·h)Reference(s)
Synechocystis PCC 6803Bidirectional hydrogenaseLight + glucose651
Arthrospira (Spirulina) maximaBidirectional hydrogenaseAutofermentation, dark, 35°C0.75-1.53
Anabaena azoticaMo nitrogenaseC2H2 + H2934
V nitrogenaseC2H2 + H24034
Anabaena variabilisMo nitrogenaseC2H2 + H22434
Nostoc (Anabaena) sp. PCC 7120Mo nitrogenasehupL/hoxL-deficient mutants50139
Anabaena variabilisMo nitrogenaseImmobilized cells, continuously for 5 months0.06-0.6134
Anabaena variabilisMo nitrogenaseImmobilized cells, sustained production after extensive CO2fixation53137
Anabaena variabilisMo nitrogenasehupSL mutant13592
Anabaena variabilis PK84V nitrogenaseHydrogenase mutant26027 (Fig. 3)
Anabaena cylindricaBidirectional hydrogenaseAnaerobic incubation, high light intensity34119
Anabaena variabilis PK84Mo nitrogenaseHydrogenase-defective isolate19126
Synechococcus PCC 7942Clostridial hydrogenase IHeterologous expression, activity in cell extracts458
Wild typeActivity in cell extracts14
Thermosynechococcus elongatusUptake hydrogenaseModified PsaE protein of PSI coupled with Ralstonia eutropha hydrogenase0.3103, 104