Characterization of hydrogen production by an ammonium insensitive Pseudo-revertant of a CBB deficient Rhodobacter capsulatus strain

► Relationship between nitrogenase control and hydrogen production in Rhodobacter capsulatus. ► Ammonium insensitive pseudo-revertants of R. capsulatus were obtained. ► Pseudo-revertant strain YO7-R3 contains A35V mutation in NifA2 protein. ► Hydrogen productivity was increased 56% in YO7-R3 strain. ► YO7-R3 strain produced 0.43 ml/ml culture hydrogen in ammonium containing medium.