The effect of different gene arrangements on the production of 3-hydroxypropionic acid in Klebsiella

• 作 者: YingLi;PingfangTian;
• 机 构: College of Life Science and Technology,Beijing University of Chemical Technology,Beijing 100029,Peop
• 出 处: The 4th International Conference on Biomass Energy Technolog
• 发表日期: 2014年期

　　Biological 3-hydroxypropionic acid(3-HP)production in Klebsiella pneumoniae is promising to replace chemical 3-HP production due to the lower cost and less pollution.In this work,vectors with different gene arrangements were constructed to examine the effect of gene expression order on 3-HP production.Two key enzyme coding genes,dhaB from K.pneumoniae and ald4 from Saccharomyces cerevisiae,were expressed under pk promoter with different order and three recombinant strains,K.pneumoniae(pk-dhaB-ald4),K.pneumoniae(pk-ald4-dhaB)and K.pneumoniae(pk-dhaB-pk-ald4)were constructed.The ALD4 enzyme activities of the three recombinants reached 2.74 U/mg,3.52 U/mg and 2.79 U/mg,respectively,which showed that prioritized ald4 expression led to the highest ALD4 activity.At the same time,the DHAB enzyme activities of the recombinants reached 2.4 U/mg,2.1 U/mg and 2.3 U/mg,indicating that limited influences were detected with the arrangements of dhaB gene.Finally,the three recombinant strains were cultured in shake flask,and 0.62 g/L,2.14 g/L and 0.55 g/L 3-HP were produced at 24 h.Collectively,disrupted gene arrangement orders resulted into different 3-HP yields and enzyme activity of ALD4 was positively related with 3-HP yield.This work provided a new insight into the relationship between gene arrangement and yield of product desired.