Improved production of 1,3-propanediol from biodiesel-derived crude glycerol by Klebsiella pneumoniae in fed-batch fermentation

In this study, crude glycerol was demonstrated as feedstock to use in the fed-batch fermentation of 1,3-propanediol production by Klebsiella pneumoniae ATCC 8724. To increase the yield and productivity of 1,3-propanediol, several factors for fed-batch fermentation were investigated, which included: initial substrate conditions, feeding strategy and fermentation conditions. Both performances of 1,3-propandiol and by-products were observed and studied for improved fed-batch fermentation. Increasing of initial working volume, continuous feeding, and culture pH switch strategy showed positive performance for this fed-batch process. The maximum 1,3-propandiol concentration, yield, and productivity were achieved 62.72 g/l, 0.73 mol/mol and 1.74 g/l/h, respectively. With the ignorable inhibitory effect, a large quantity of crude glycerol from industrial biodiesel process would be an attractive feedstock for value-added chemical, 1,3-propandiol, manufacture. The improvement of fed-batch fermentation could also be achieved by strategy optimization in further applications.