Light-Driven Biosynthesis of myo-Inositol Directly From CO2 in Synechocystis sp. PCC 6803

Frontiers in Microbiology

Tao Sun¹  Weiwen Zhang¹  Lei Chen²  Xiaoshuai Wang²  Jing Liu⁵ 

[1] Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China;Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China;Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, China;Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China;School of Life Sciences, Tianjin University, Tianjin, China;

关键词: myo-inositol;    cyanobacteria;    photosynthetic cell factory;    small RNA tools;    synthetic biology;   

DOI  :  10.3389/fmicb.2020.566117

来源: DOAJ

【 摘 要 】

myo-inositol (MI) is an essential growth factor, nutritional source, and important precursor for many derivatives like D-chiro-inositol. In this study, attempts were made to achieve the “green biosynthesis” of MI in a model photosynthetic cyanobacterium Synechocystis sp. PCC 6803. First, several genes encoding myo-inositol-1-phosphate synthases and myo-inositol-1-monophosphatase, catalyzing the first or the second step of MI synthesis, were introduced, respectively, into Synechocystis. The results showed that the engineered strain carrying myo-inositol-1-phosphate synthase gene from Saccharomyces cerevisiae was able to produce MI at 0.97 mg L–1. Second, the combined overexpression of genes related to the two catalyzing processes increased the production up to 1.42 mg L–1. Third, to re-direct more cellular carbon flux into MI synthesis, an inducible small RNA regulatory tool, based on MicC-Hfq, was utilized to control the competing pathways of MI biosynthesis, resulting in MI production of ∼7.93 mg L–1. Finally, by optimizing the cultivation condition via supplying bicarbonate to enhance carbon fixation, a final MI production up to 12.72 mg L–1 was achieved, representing a ∼12-fold increase compared with the initial MI-producing strain. This study provides a light-driven green synthetic strategy for MI directly from CO2 in cyanobacterial chassis and represents a renewable alternative that may deserve further optimization in the future.

【 授权许可】

Unknown