THE INHIBITION BY NITRATE OF ENZYME FORMATION DURING GROWTH OF ESCHERICHIA COLI

Abstract

Hydrogenase, formic dehydrogenase, and formic hydrogenlyase activity were absent in a suspension of E. coli, "Texas" strain which had been harvested from a basal medium containing vitamin-free acid-hydrolyzed casein and nitrate. The nitrate was shown to be the cause of the inhibition noted. The time of addition of the nitrate to the growing cultures influenced its effectiveness as an inhibitor. Increasing concns. of casein hydrolysate were found to antagonize the inhibition effect of nitrate.