Lipid-polyamide-polyethyleneimine microcapsules for immobilization of free cofactors and multienzyme system.

Lipid-polyamide membrane microcapsules containing multienzyme system convert ammonia into glutamate. L-Glutamic dehydrogenase, alcohol dehydrogenase, NAD+, and alpha-ketoglutarate retained within the microcapsules do not leak out. This way the multienzyme system can recycle the free cofactor NAD+ and synthesize glutamate from external lipophilic ammonia diffusing into the microcapsules. By using polyethyleneimine instead of hemoglobin as microcapsule filler it is possible to obtain higher conversion rates and to increase the storage stability of the recycling activity.