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.
Appl Biochem Biotechnol. 2011 Dec;165(7-8):1532-42. doi: 10.1007/s12010-011-9373-1. Epub 2011 Sep 30.
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.
1,3-丙二醇（1,3-PD）的生物合成在消耗 NADH 以调节肺炎克雷伯氏菌细胞内还原当量平衡方面起着关键作用。本研究旨在通过甘油和木糖的共发酵来增加还原当量，以提高 1,3-PD 的产量。添加木糖作为共底物会产生更多的还原当量，并促进细胞生长。在微需氧条件下进行分批发酵时，1,3-PD 的浓度、甘油转化率和生物量（OD（600））相对于共发酵分别显著提高了 9.1%、20%和 15.8%。与单独使用甘油相比，还原当量（NADH）增加了 1-3mg/g（细胞干重）。此外，2,3-丁二醇也作为主要副产物双产量。在以木糖为共底物的补料分批发酵中，最终的 1,3-PD 浓度、甘油转化率和生产率分别从 60.78g/L 提高到 67.21g/L、0.52mol/mol 提高到 0.63mol/mol、1.64g/l/h 提高到 1.82g/l/h。
