Microbial production of 1,3-propanediol from glycerol by encapsulated Klebsiella pneumoniae

Klebsiella pneumoniae was encapsulated in the NaCS/PDMDAAC (sodium cellulose sulfate/poly-dimethyl-diallyl-ammonium chloride) microcapsule to produce 1,3-propanediol (PDO) from glycerol. Fermentations including batch culture, fed-batch culture and continuous culture were carried out in shake flasks and a fixed-bed bioreactor. Results showed that the NaCS/PDMDAAC microcapsule has desirable properties – such as biomass enrichment in the microcapsule (6.84 g/L capsule, 2.6-fold higher than that of free cell culture), enhanced substrate tolerance and stable activity of cells, operation convenience for continuous culture – for the microbial production of 1,3-propanediol. A 1,3-propanediol concentration of 63.1 g/L with a yield of 0.65 mol PDO/mol glycerol was obtained in the batch culture. The encapsulated cells remained its activity for 67 h in the fed-batch culture and produced 1,3-propanediol at a concentration of 51.86 g/L. In the continuous culture, 1,3-propanediol was provided at a productivity of 4.49 g/L h, a concentration of 13.6 g/L, and a yield of 0.43 mol PDO/mol glycerol at a dilution rate of 0.33 h−1.