title: Microbial fed-batch production of 1,3-propanediol by Klebsiella pneumoniae under micro-aerobic conditions.
abstract: The microbial production of 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae under micro-aerobic conditions was investigated in this study. The experimental results of batch fermentation showed that the final concentration and yield of 1,3-PD on glycerol under micro-aerobic conditions approached values achieved under anaerobic conditions. However, less ethanol was produced under microaerobic than anaerobic conditions at the end of fermentation. The batch micro-aerobic fermentation time was markedly shorter than that of anaerobic fermentation. This led to an increment of productivity of 1,3-PD. For instance, the concentration, molar yield, and productivity of 1,3-PD of batch micro-aerobic fermentation by K. pneumoniae DSM 2026 were 17.65 g/l, 56.13%, and 2.94 g l(-1) h(-1), respectively, with a fermentation time of 6 h and an initial glycerol concentration of 40 g/l. Compared with DSM 2026, the microbial growth of K. pneumoniae AS 1.1736 was slow and the concentration of 1,3-PD was low under the same conditions. Furthermore, the microbial growth in fed-batch fermentation by K. pneumoniae DSM 2026 was faster under micro-aerobic than anaerobic conditions. The concentration, molar yield, and productivity of 1,3-PD in fed-batch fermentation under micro-aerobic conditions were 59.50 g/l, 51.75%, and 1.57 g l(-1) h(-1), respectively. The volumetric productivity of 1,3-PD under microaerobic conditions was almost twice that of anaerobic fed-batch fermentation, at 1.57 and 0.80 g l(-1) h(-1), respectively.
authors.affiliation: Department of Biotechnology, Dalian University of Technology, Linggong Road 2, 116023 Dalian, PR China.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: D-J
authors.initials: DJ
authors.lastname: Zhang
authors.forename: W-T
authors.initials: WT
authors.lastname: Qi
authors.forename: S-J
authors.initials: SJ
authors.lastname: Gao
authors.forename: Z-L
authors.initials: ZL
authors.lastname: Xiu
authors.forename: P
authors.initials: P
authors.lastname: Xu
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D003470:Culture Media; D005285:Fermentation / Q000187:drug effects; D005990:Glycerol / Q000378:metabolism*; D007711:Klebsiella pneumoniae / Q000254:growth & development* / Q000378:metabolism*; D011409:Propylene Glycols / Q000378:metabolism*
chemical_list: D003470:Culture Media; D011409:Propylene Glycols; C041787:1,3-propanediol; D005990:Glycerol