Zhu Chengqian, Jiang Xiao, Zhang Yongqiang, Lin Jie, Fu Shuilin, Gong Heng
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
Biotechnol Lett. 2015 Sep;37(9):1783-90. doi: 10.1007/s10529-015-1851-z. Epub 2015 May 10.
To improve 1,3-propanediol production in Klebsiella pneumoniae, the effects of puuC expression in lactate- and lactate/2,3-butanediol-deficient strains were assessed.
Overexpression of puuC (encoding an aldehyde dehydrogenase) inhibited 1,3-propanediol production and increased 3-hydroxypropionic acid formation in both lactate- and lactate/2,3-butanediol-deficient strains. An improvement in 1,3-propanediol production was only achieved in a lactate-deficient strain via moderate expression of puuC; at the end of the fermentation, 1,3-propanediol productivity increased by 14% compared with the control. Further comparative analysis of the metabolic flux distributions in different strains indicated that 3-hydroxypropionic acid formation could play a considerable role in cell metabolism in K. pneumoniae.
An improvement in 3-hydroxypropionic acid formation would be beneficial for cell metabolism, which can be accomplished by enhancing 1,3-propanediol productivity in a lactate-deficient strain via moderate expression of puuC.
为提高肺炎克雷伯菌中1,3 - 丙二醇的产量，评估了在缺乏乳酸和乳酸/2,3 - 丁二醇的菌株中表达puuC的效果。
在缺乏乳酸和乳酸/2,3 - 丁二醇的菌株中，puuC（编码一种醛脱氢酶）的过表达抑制了1,3 - 丙二醇的产生，并增加了3 - 羟基丙酸的形成。仅在缺乏乳酸的菌株中通过适度表达puuC实现了1,3 - 丙二醇产量的提高；在发酵结束时，与对照相比，1,3 - 丙二醇的生产率提高了14%。对不同菌株中代谢通量分布的进一步比较分析表明，3 - 羟基丙酸的形成在肺炎克雷伯菌的细胞代谢中可能起相当大的作用。
改善3 - 羟基丙酸的形成将有利于细胞代谢，这可以通过在缺乏乳酸的菌株中适度表达puuC来提高1,3 - 丙二醇的生产率来实现。
