The efficient green bio-manufacturing of Vitamin K₂: design, production and applications

Vitamin K₂, also known as methylnaphthoquinone, is a crucial fat-soluble nutrient necessary for the human body. The biological production of Vitamin K₂ has received widespread attention due to its environmental friendliness and maneuverability in recent years. This review provides insights into the modular metabolic pathways of Vitamin K₂, lays the foundation for microbial metabolic flow balancing, cofactor engineering and dynamic regulation, and realizes the production of Vitamin K₂ by synthesizing artificial cells from scratch. With the intensive development of modern fermentation technology, methods for the preparation of Vitamin K₂ using the fermentation strategies of co-culturing and biofilm reactors have emerged. In prokaryotes, the introduction of heptenyl pyrophosphate synthase (HepPPS) and mevalonate acid (MVA) pathway solved the problem of insufficient precursors for Vitamin K₂ production but still did not meet the market demand. Therefore, enhancing expression through multi-combinatorial metabolic regulation and innovative membrane reactors is an entry point for future research. Due to the light-induced decomposition and water-insoluble nature of Vitamin K₂, the secretion regulation and purification processing also need to be considered in the actual production. Also, it summarizes the research progress of Vitamin K₂ in the food and pharmaceutical fields. Additionally, the future development trend and application prospect of Vitamin K₂ are also discussed to provide guidance for Vitamin K₂ biosynthesis and application.