摘要：The variable sensitivity of Zymomonas mobilis iron-containing alcohol dehydrogenase isoenzyme(ADH II) to cyanide and oxygen was studied. Th e cyanide-sensitivity of ADH II was highest incells grown under conditions of vigorous aeration, in which intracellular NADH concentrationwas low. Anaerobically grown bacteria, as well as those cultivated aerobically in the presence ofcyanide, maintained a higher intracellular NADH pool along with a more cyanide-resistant ADH II.In aerobically grown permeabilized cells, cyanide caused gradual inhibition of ADH II, which waslargely prevented by externally added NADH, and, to lesser extent, by NAD. It was demonstratedthat cyanide acted as a competitive inhibitor of ADH II, competing with nicotinamide nucleotides.NADH increased both the cyanide resistance and oxygen resistance of ADH II.
