A study in UF-membrane reactor on activity and stability of nitrile hydratase from Microbacterium imperiale CBS 498-74 resting cells for propionamide production

Nitrile bioconversion by Microbacterium imperiale CBS 498-74 resting cells in batch and ultrafiltration membrane bioreactors

“…The proper choice of operational conditions in acrylonitrile bioconversion makes the amidase activity negligible as compared with NHase activity and near 100% conversion yields into amide are possible [2,[5][6][7][8].…”

UF‐Membrane Bioreactors for Kinetics Characterization of Nitrile Hydratase–Amidase‐Catalyzed Reactions: A Short Survey

“…Acrylamide in the effl uent could be concentrated, restoring the initial substrate concentration in the product stream after each cycle and feeding it to the subsequent reactor. The apparent lack of amidase activity that we also observed in the propionamide production [33] could be attributed either to the low temperature chosen to perform the CSMR runs or to amidase substrate (acrylamide, propionamide) inhibition. In benzonitrile biotransformation in CSMR, the correct choice of operational conditions (mainly temperature and residence time) permitted to arrest the nitrile hydratase/amidase reaction either at the amide intermediate or at the fi nal corresponding acid stage [34] .…”

“…The propionitrile nitrile hydratase -catalyzed reaction presented kinetics inhibited by high substrate concentrations that were clearly evidenced in the CSMR, as revealed in [33] . The kinetic parameters for nitrile hydratase -catalyzed reactions of 1.…”

“…The analytical conditions adopted for benzonitrile, benzamide and benzoic acid determination are fully described in [34] , and those for nicotinic acid and nicotinamide in [35] . Propionitrile and propionamide were identifi ed by their retention time in gas chromatography analyses [33] .…”

“…Aliphatic and aromatic substrates have been tested using resting cells as a biocatalyst. In particular, nitrile hydratase activity was characterized in the presence of acrylonitrile [31,32] , propionitrile [33] , benzonitrile [34] , and amidase with nicotinamide [35] . Amidase activity was investigated either independently, in the presence of the exogenous matching amide, or as part of the cascade system, where the matching amide was generated by the nitrile hydratase activity.…”