Shi Yi, Lu Shuhuan, Zhou Xiao, Wang Xinhui, Zhang Chenglong, Wu Nan, Dong Tianyu, Xing Shilong, Wang Ying, Xiao Wenhai, Yao Mingdong
Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Frontier Research Institute for Synthetic Biology, Tianjin University, China.
Synth Syst Biotechnol. 2024 Aug 16;10(1):58-67. doi: 10.1016/j.synbio.2024.08.004. eCollection 2025.
Vitamin A is a micronutrient critical for versatile biological functions and has been widely used in the food, cosmetics, pharmaceutical, and nutraceutical industries. Synthetic biology and metabolic engineering enable microbes, especially the model organism (generally recognised as safe) to possess great potential for the production of vitamin A. Herein, we first generated a vitamin A-producing strain by mining β-carotene 15,15'-mono(di)oxygenase from different sources and identified two isoenzymes and with comparable catalytic properties but different catalytic mechanisms. Combinational expression of isoenzymes increased the flux from β-carotene to vitamin A metabolism. To modulate the vitamin A components, retinol dehydrogenase 12 from was introduced to achieve more than 90 % retinol purity using shake flask fermentation. Overexpressing enhanced the reduced nicotinamide adenine dinucleotide phosphate pool, and the titer of vitamin A was elevated by almost 46 %. Multi-copy integration of the key rate-limiting step gene further improved the synthesis of vitamin A. Consequently, the titer of vitamin A in the strain harbouring the Ura3 marker was increased to 588 mg/L at the shake-flask level. Eventually, the highest reported titer of 5.21 g/L vitamin A in was achieved in a 1-L bioreactor. This study unlocked the potential of for synthesising vitamin A in a sustainable and economical way, laying the foundation for the commercial-scale production of bio-based vitamin A.
维生素A是一种对多种生物学功能至关重要的微量营养素，已广泛应用于食品、化妆品、制药和营养保健品行业。合成生物学和代谢工程使微生物，特别是模式生物（一般公认为安全）在生产维生素A方面具有巨大潜力。在此，我们首先通过挖掘不同来源的β-胡萝卜素15,15'-单（双）加氧酶生成了一株产维生素A的菌株，并鉴定出两种具有可比催化特性但催化机制不同的同工酶。同工酶的组合表达增加了从β-胡萝卜素到维生素A代谢的通量。为了调节维生素A的成分，引入了来自的视黄醇脱氢酶12，通过摇瓶发酵实现了超过90%的视黄醇纯度。过表达增强了还原型烟酰胺腺嘌呤二核苷酸磷酸池，维生素A的产量提高了近46%。关键限速步骤基因的多拷贝整合进一步改善了维生素A的合成。因此，携带Ura3标记的菌株在摇瓶水平下维生素A的产量提高到了588 mg/L。最终，在1-L生物反应器中实现了报道的最高维生素A产量5.21 g/L。这项研究释放了以可持续和经济的方式合成维生素A的潜力，为生物基维生素A的商业规模生产奠定了基础。
