Novel Mode Engineering for β-Alanine Production in Escherichia coli with the Guide of Adaptive Laboratory Evolution

Microorganisms

Jian Xu¹  Li Zhou¹  Zhemin Zhou¹  Meng Yin¹ 

[1] The Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China;

关键词: anaerobic fermentation;    energy regulation;    CO2 fixation;    adaptive laboratory evolution;    β-alanine production;   

DOI  :  10.3390/microorganisms9030600

来源: DOAJ

【 摘 要 】

The strategy of anaerobic biosynthesis of β-alanine by Escherichia coli (E. coli) has been reported. However, the low energy production under anaerobic condition limited cell growth and then affected the production efficiency of β-alanine. Here, the adaptive laboratory evolution was carried out to improve energy production of E. coli lacking phosphoenolpyruvate carboxylase under anaerobic condition. Five mutants were isolated and analyzed. Sequence analysis showed that most of the consistent genetic mutations among the mutants were related with pyruvate accumulation, indicating that pyruvate accumulation enabled the growth of the lethal parent. It is possible that the accumulated pyruvate provides sufficient precursors for energy generation and CO₂ fixing reaction catalyzed by phosphoenolpyruvate carboxykinase. B0016-100BB (B0016-090BB, recE::FRT, mhpF::FRT, ykgF::FRT, mhpB:: mhpB *, mhpD:: mhpD *, rcsA:: rcsA *) was engineered based on the analysis of the genetic mutations among the mutants for the biosynthesis of β-alanine. Along with the recruitment of glycerol as the sole carbon source, 1.07 g/L β-alanine was generated by B0016-200BB (B0016-100BB, aspA::FRT) harboring pET24a-panD-AspDH, which was used for overexpression of two key enzymes in β-alanine fermentation process. Compared with the starting strain, which can hardly generate β-alanine under anaerobic condition, the production efficiency of β-alanine of the engineered cell factory was significantly improved.

【 授权许可】

Unknown