GLYCEROL DEHYDRATASE ACTIVITY - THE LIMITING STEP FOR 1,3-PROPANEDIOLPRODUCTION BY CLOSTRIBIUM-BUTYRICUM DSM-5431

Glycerol catabolism by Clostridium butyricum DSM 5431 into acetate, bu tyrate and 1,3-propanediol (1,3-PD) was studied in chemostat culture. The fact that the intracellular concentrations of NADH (18-22 mu mol g (-1) dry cell mass) mere extremely high suggested that the dehydratase activity was the rate limiting step in 1,3-PD formation. This limitat ion was proved by the addition of propionaldehyde, another substrate o f propanediol dehydrogenase, into the culture medium. This resulted in an increase in (i) glycerol utilization, (ii) biomass formation and ( iii) product biosynthesis.