Hussain Muhammad Hammad, Hong Qi, Zaman Waqas Qamar, Mohsin Ali, Wei Yanlong, Zhang Ning, Fang Hongqing, Wang Zejian, Hang Haifeng, Zhuang Yingping, Guo Meijin
State Key Laboratory of Bioreactor Engineering East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, PR China.
Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering National University of Sciences and Technology (NUST), Sector H-12, Islamabad, 44000, Pakistan.
Synth Syst Biotechnol. 2021 Apr 22;6(2):85-94. doi: 10.1016/j.synbio.2021.04.001. eCollection 2021 Jun.
The stability and high productivity of heterogeneous terpenoid production in expression system is one of the most key issues for its large scale industrialization. In the current study on taking lycopene biosynthesis as an example, an integrated system has been generated successfully, which resulted into stable and high lycopene production. In this process, two modules of mevalonate (MVA) pathway and one module of lycopene expression pathway were completely integrated in the chromosome. Firstly, the copy number and integrated position of three modules of heterologous pathways were rationally optimized. Later, a strain DH416 equipped with heterogeneous expression pathways through chromosomal integration was efficiently derived from parental strain DH411. The evolving DH416 strain efficiently produced the lycopene level of 1.22 g/L (49.9 mg/g DCW) in a 5 L fermenter with mean productivity of 61.0 mg/L/h. Additionally, the integrated strain showed more genetic stability than the plasmid systems after successive 21st passage.
异源萜类化合物在表达系统中生产的稳定性和高产量是其大规模工业化的最关键问题之一。在当前以番茄红素生物合成为例的研究中，成功构建了一个整合系统，该系统实现了番茄红素的稳定高产。在此过程中，甲羟戊酸（MVA）途径的两个模块和番茄红素表达途径的一个模块被完全整合到染色体中。首先，对异源途径的三个模块的拷贝数和整合位置进行了合理优化。随后，通过染色体整合配备了异源表达途径的菌株DH416从亲本菌株DH411高效衍生而来。进化后的DH416菌株在5 L发酵罐中能够高效生产番茄红素，产量达到1.22 g/L（49.9 mg/g干细胞重量），平均生产率为61.0 mg/L/h。此外，经过连续21代传代后，整合菌株比质粒系统表现出更高的遗传稳定性。
