The production of 1,3-propanediol from mixtures of glycerol and glucose by a Klebsiella pneumoniae mutant deficient in carbon catabolite repression

► We prepared a crr mutant strain of Klebsiella pneumonia mutant, in which carbon catabolite repression (CCR) was abolished. ► Production of 1,3-propanediol from glycerol upon fermentation of the crr mutant increased by the presence of glucose. ► This is the first report to show that elimination of CCR in K. pneumoniae strains used for 1,3-PD biosynthesis. In the present study, mutant strain of Klebsiella pneumoniae with deletion of the crr gene encoding EIIAGlc (a component of the glucose-specific phosphoenolpyruvate-dependent transferase system [PTS]) was prepared. This eliminated the ability of the strain to mediate carbon catabolite repression (CCR). Production of 1,3-propanediol (1,3-PD) from glycerol by the crr mutant strain was enhanced (compared to that of the parent) in the presence of glucose. Using molasses as a co-substrate of glycerol, the maximum yield of 1,3-PD was 60.4% greater (81.2g/l) than that obtained when glycerol was used alone, under optimum fermentation conditions.