State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Bioresour Technol. 2013 Jan;128:505-12. doi: 10.1016/j.biortech.2012.10.143. Epub 2012 Nov 8.
Fed-batch cultures of Klebsiella pneumoniae expressing Escherichia coli aldH were performed under microaerobic conditions to investigate the effects on metabolites production. Increasing the aeration rate enhanced cell growth and 3-hydroxypropionic acid (3-HP) production, but reduced 1,3-propanediol (1,3-PDO) formation. The recombinant strain K. pneumoniae/pUC18kan-aldHec produced 48.9 g/L of 3-HP and 25.3g/L of 1,3-PDO with an overall yield of 0.66 mol/mol in 28 h at an aeration rate of 1.5 vvm; however, under fully aerobic condition, no 3-HP and 1,3-PDO were produced due to the repression of dha operon. The flux through the reaction catalyzed by glycerol dehydratase and the split ratio of 1,3-PDO were negatively correlated with the aeration rate, even though the 3-HP level showed a positive trend. This study demonstrated that the relative amounts of 3-HP and 1,3-PDO can be controlled by the aeration rate.
在微氧条件下进行表达大肠杆菌 aldH 的肺炎克雷伯氏菌的分批补料培养，以研究其对代谢产物生产的影响。增加通气速率可以促进细胞生长和 3-羟基丙酸（3-HP）的生产，但会降低 1,3-丙二醇（1,3-PDO）的形成。重组菌株 K. pneumoniae/pUC18kan-aldHec 在通气速率为 1.5 vvm 下 28 小时内产生 48.9 g/L 的 3-HP 和 25.3 g/L 的 1,3-PDO，总产率为 0.66 mol/mol；然而，在完全有氧条件下，由于 dha 操纵子的抑制，没有产生 3-HP 和 1,3-PDO。甘油脱水酶催化的反应通量和 1,3-PDO 的分裂比与通气速率呈负相关，尽管 3-HP 水平呈正趋势。本研究表明，3-HP 和 1,3-PDO 的相对量可以通过通气速率来控制。
