Patent ID: 8623624

Claim:
A method for biotechnological production of a hydrogen carrier, comprising contacting a nitrogen or a nitrogenous compound with a transformed photosynthetic cyanobacteria which has altered expression of a plurality of genes involved in the synthesis, assimilation and transportation of the ammonium produced by said photosynthetic cyanobacteria, wherein (a) the products of the genes involved in the synthesis of said ammonium comprise (1) co-activator PII-interacting protein X (PipX) which forms a complex with a nitrogen control protein A (NtcA), wherein said PipX-NtcA complex activates said NtcA, resulting in a concomitant activation of the gene nitrogenase, which in turn increases the yield of the ammonium generated by said photosynthetic cyanobacteria; and (b) the products of the genes involved in the assimilation of ammonium comprise (1) glutamate synthatase, which assimilates ammonium into glutamate, thereby reducing the yield of ammonium; and (2) glutamine synthetase inhibition factors IF7 and IF17 having molecular weights of 7 kpa and 17 kpa, respectively, wherein the inhibition factors inhibit glutamine synthase, thereby inhibiting the assimilation of ammonium into glutamate and concomitantly increasing the yield of ammonium; and (c) the products of the genes involved in the transportation of ammonium comprise (1) bifunctional ammonium channels, wherein the expression of at least one gene in each of (a), (b) and (c) is altered in said transformed photosynthetic bacteria and wherein ammonium product is provided as said hydrogen carrier.