Fusion of Glutamate Dehydrogenase and Formate Dehydrogenase Yields a Bifunctional Efficient Biocatalyst for the Continuous Removal of Ammonia

A novel fusion protein has been rationally designed, combining the hexameric glutamate dehydrogenase from Clostridium symbiosum with dimeric formate Candida boidinii . The former enzyme consumes ammonia for reductive amination of α-ketoglutarate using NADH, while latter biocatalyst regenerates continuously cofactor. This enzymes opens new perspectives detection and removal ammonia. bifunctional successfully created, expressed, then characterized. two fused domains retained identical properties catalytic activity individual enzymes. Additionally, immobilization on a methacrylate resin optimized assembly providing reusable stable biocatalyst. is an example protein, so that efficiency sustainability process are enhanced. immobilized could be recycled 10 times retaining still half initial activity. Such preparation outperforms co-immobilized wild-type in conversion 300 mM ammonia, which carried out also continuous mode.