3-propanediol from glycerol by Klebsiella pneumoniae encapsulated in NaCS/PDMDAAC capsules with a liquid core was investigated.The cell growth
glycerol consumption
1
3-propanediol accumulation by encapsulated K.pneumoniae were compared with free culture in flasks.The immobilized K.pneumoniae was also cultured in a packed bed reactor.The biomass in microcapsules reached 6 g·L-1
far higher than 2.5 g·L-1 in flask for free culture.Glycerol was consumed completely in 12 h for immobilized cells
compared with 27 h for free cells.The encapsulated cells produced 1
3-propanediol of 13 g·L-1 in fermentation broth
lower than 17.5 g·L-1 in free culture.If 1
3-propanediol in microcapsules was considered
the yield (YP/S) for immobilized cell was 0.613 mol·mol-1
which was higher than 0.545 mol·mol-1 for free culture.For batch fermentations in the packed bed reactor
the method of increasing substrate concentration was adopted to increase the final 1
3-propanediol concentration
and the maximal 1
3-propanediol concentration reached 58.1 g·L-1 with molar yield of 0.596 mol·mol-1 and productivity of 5.28 g·L-1·h-1 at the initial glycerol concentration of 120 g·L-1.Six batches of fermentation in packed bed reactor was carried out and the results could be reproduced.