| 초록 |
3-Hydroxypropionic acid (3-HP), which can be converted into many chemicals such as acrylic acid and acrylamide is an important platform chemical. It can be biologically produced from glycerol by two enzymatic reactions. The pathway has been proved efficient, but imbalance between the rates of the two enzymatic reactions often results in the accumulation of the toxic 3-HPA. In this study, we used UTR engineering to increase the activities of glycerol dehydratase (GDHt) and aldehyde dehydrogenase (ALDH) for the high conversion of glycerol to 3-HP. Thereafter, the activity of GDHt was precisely controlled to avoid the accumulation of 3-HPA by varying expression of dhaB1, a gene encoding a main subunit of GDHt. The optimally balanced E. coli HGL_DBK4 showed a substantially enhanced 3-HP titer (40.51 g/L) and productivity (1.35 g/L/h) compared with the parental strain. Especially, the yield on glycerol, 0.97 g 3-HP/g glycerol, in a fed-batch experiment, was the highest ever reported. |
