| 摘要： |
In order to produce 2,4-diacetylphloroglucinol (2,4-DAPG) inE. coli, the key synthases coding byphlACBDgene cluster from the strainPseudomonas fluorescensCHA0 were overexpressed inE. coliBL21 (DE3). ThemarA,phlEandaccgenes were also overexpressed to enhance 2,4-DAPG biosynthesis. Then the fermentation conditions were optimized to improve the concentration of 2,4-DAPG. The results showed that the recombinantE. colicould produce few 2,4-DAPG with only thephlACBDgene cluster. The synthetic ability of 2,4-DAPG could be increased by expressing theacc,marAandphlEgenes in shake-flasks cultivation. The effects of phloroglucinol, initial pH, temperature and trace elements on 2,4-DAPG biosynthesis were also investigated. Based on the optimal fermentation conditions obtained from the shake-flasks cultivation, fed-batch fermentation of strain Z3 in a 5 L bioreactor was conducted to produce 2,4-DAPG. Finally, the concentration of 2,4-DAPG was 179 mg/L after induction for 36 h by fed-batch fermentation. To the best of our knowledge, this is the highest 2,4-DAPG production reported inE. coli. This work showed the potential application of engineeredE. colito get high production of target compounds. |
