TABLE 3

Comparison of H2 production and nitrogenase activity after nitrate step down for 24 h in wild-type Cyanothece sp. strain PCC 7822, a ΔhupL mutant, and a complemented ΔhupL strain

StrainExtent of H2 production (μmol H2/mg Chl a/day)Extent of nitrogenase activity (μmol N2 reduced/mg Chl a1/day1)
Wild type2,474.4 ± 496.82,140.8 ± 340.8
ΔhupL mutant84.0 ± 21.67.2 ± 2.4
C-ΔhupL strain2,224.8 ± 434.41,759.2 ± 192.0