1,3-Propanediol Fermentation with the by-Product Glycerol from Biodiesel Production by a Genetic Modified Klebsiella pneumoniae

Nowadays, the utilization of the by-product glycerol has become a common problem with the large amount of biodiesel production. This paper studied the conversion of the by-product glycerol of biodiesel production by Klebsiella pneumonia to 1,3-propanediol. The crude glycerol could be used directly without refining by a lactate dehydrogenase deficient K. pneumoniae and the lactic acid concentration was very low. In the fed-batch fermentation of 7L fermenter, 93.3g/l 1,3-propanediol was obtained and lactic acid concentration was just 2g/l. Analysis showed that D-type lactic acid synthesis was reduced obviously. The fermentation also was scaled up on the 42L fermenter. 1,3-propanediol and 2,3-Butanediol concentration reached 81.5g/l and 33.8g/l, respectively. No lactic acid was detected. The demonstration fermentation in 5000L fermenter was also successfully performed. The final 1,3-propanediol concentration and productivity was 87g/l and 1.2g/(lh). This work was considered useful to the integrated production of biodiesel and 1,3-propanediol.