title: Enhanced reducing equivalent generation for 1,3-propanediol production through cofermentation of glycerol and xylose by Klebsiella pneumoniae.
abstract: 1,3-Propanediol (1,3-PD) biosynthesis plays a key role in NADH consumption to regulate the intracellular reducing equivalent balance of Klebsiella pneumoniae. This study aimed to increase reducing equivalent for enhancing 1,3-PD production through cofermentation of glycerol and xylose. Adding xylose as cosubstrate resulted in more reducing equivalent generation and higher cell growth. In batch fermentation under microaerobic condition, the 1,3-PD concentration, conversion from glycerol, and biomass (OD(600)) relative to cofermentation were increased significantly by 9.1%, 20%, and 15.8%, respectively. The reducing equivalent (NADH) was increased by 1-3 mg/g (cell dry weight) compared with that from glycerol alone. Furthermore, 2,3-butannediol was also doubly produced as major byproduct. In fed-batch fermentation with xylose as cosubstrate, the final 1,3-PD concentration, conversion from glycerol, and productivity were improved evidently from 60.78 to 67.21 g/l, 0.52 to 0.63 mol/mol, and 1.64 to 1.82 g/l/h, respectively.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing 210009, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jin
authors.forename: Sheng-Guo
authors.initials: SG
authors.lastname: Lu
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.forename: Fang
authors.initials: F
authors.lastname: Luo
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
mesh_terms: D018533:Biomass; D005285:Fermentation; D005990:Glycerol / Q000378:metabolism*; D007711:Klebsiella pneumoniae / Q000254:growth & development / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D011409:Propylene Glycols / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism*
chemical_list: D011409:Propylene Glycols; D009243:NAD; C041787:1,3-propanediol; D014994:Xylose; D005990:Glycerol