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Reduction of nitro-substituted compounds, 1,4-benzodiazepine-2-ones, dibenzo[b,f]-1,4-diazepines, quinolones, and quinoxalinones, by Escherichia coli cells was studied. Physicochemical methods demonstrated the formation of corresponding amines. 4-(p-Nitrophenyl)-1H-6-R-quinolones-2 were nor reduced by Escherichia coli cells. Regiospecific reduction of 2,4-dinitro-5H-11-(p-R-phenyl)-dibenzo[b,f]-1,4-diazepines and 4-(2'-R-3',5'-dinitro)-benzoyl-3,4-dihydroquinoxalinones-2 was shown to result in the formation of 2-nitro-4-amino-5H-11-(p-R-phenyl)-dibenzo[b,f]-1,4-diazepines and 4-(2'-R-3'-nitro-5'-amino)-benzoyl-3,4-dihydroquinoxalinones-2, respectively. Methods for microbiological reduction of nitro compounds and immobilization of Escherichia coli cells into carrageenan and its modified forms were elaborated.

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.

Nitroreduction of 2,4-dinitro-5H-11-p-R-phenyl-[b,f]-1,4-diazepines and 4-(2'-R-3',5'-dinitro)benzoyl-3,4-dihydroquinoxalinones-2 by E. coli with formation of 2-nitro-4-amino-11-p-R-phenyldibenzo-[b,f]-1,4-diazepines and 4-(2'-R-3'-nitro-5'-amino)-benzoyl-3,4-dihydroquinoxalinones-2 has been demonstrated using a set of physical and chemical methods.