K. Yagi et al., REMOVAL OF INHIBITION BY AMMONIUM ION IN NITROGENASE-DEPENDENT HYDROGEN EVOLUTION OF A MARINE PHOTOSYNTHETIC BACTERIUM, RHODOPSEUDOMONAS SPSTRAIN W-1S, Applied biochemistry and biotechnology, 45-6, 1994, pp. 429-436
The addition of NH4Cl at concentrations of more than 1 mM completely i
nhibited nitrogenase-dependent hydrogen evolution using 1 mM succinate
as a substrate in the marine photosynthetic bacterium Rhodopseudomona
s sp. strain W-1S. However, cells could derepress nitrogenase within 6
h in the presence of NH4Cl. The inhibition by 1 mM NH4Cl was removed
by increasing the concentration of the substrate for hydrogen evolutio
n. The addition of L-methionine-D,L-sulfoximine (MSX), an inhibitor of
glutamine synthetase (GS), also removed the inhibition by 1 mM NH4Cl.
These results indicated that under an argon gas phase, nitrogenase-de
pendent hydrogen evolution is inhibited by ATP-consuming GS activity i
n the presence of NH4Cl. We isolated a mutant strain, CR-8, which is c
apable of active hydrogen evolution in the presence of 1 mM NH4Cl.