Effect of alternative aeration on key enzymes and coenzymes in 1,3-propanediol production by Klebsiella pneumoniae

The effect of air in alternative aeration model on 1,3-propandiol anaerobic biosynthesis was studied by examining the activities of key enzymes and coenzymes in Klebsiella pneumoniae. Aerating air in the fore stage (the 12 h) for 4 h, the activities of glycerol dehydrogenase and 1,3-PD oxidoreductase were 1.5 times and 18% higher than control respectively, and the concentration of 1,3-propanediol was 16% higher than control. Aerating air in the later stage (the 28 and the 48 h), the activity of glycerol dehydrogenase changed little, while the activity of 1,3-PD oxidoreductase and 1,3-PD concentration both declined. In the fore stage, the aeration had no effect on the concentrations of NAD and NADH, while in the later stage cell growth ceased, and the concentrations of NAD and NADH declined consequently.