Reduction of nitro-substituted 1,2-dihydro-3H-1,4-benzodiazepine- 2-ones by E. coli cells immobilized in carrageenan

Reduction of nitro-substituted 1,2-dihydro-3H-1,3-benzodiazepine-2-ones by E. coli cells immobilized in carrageenan was studied. The corresponding amines are the sole products with a 100% yield as compared to the native cells. Conditions for immobilization of E. coli cells in the home-produced carrageenan was worked out: the cell to carrageenan ratio is 1:10 (w/w), granulation in toluene at 0-(+)4 degrees, treatment with 0.3-0.4 M KCl. The carrageenan-immobilized cells are stable upon storage, repeated usage (after 10 cycles about 80% of the initial activity is retained), and when being used in column fermenters.