关键词: 代谢工程；酿酒酵母；柠檬烯；合成策略

Abstract: Plant terpenoids are natural secondary metabolites derived from the structural units of isoprene with a molecular formula of C5H8. Limonene is a monoterpene compound, which has many functions such as antibacterial, flavor-enhancing, anticancer, and anticough functions, so it has a wide range of applications in food, pharmaceutical, cosmetic, and other fields. At present, limonene is mainly produced by extraction from plants, which is limited by factors such as seasonal raw materials, complicated separation and purification, and low yield of limonene, while chemical synthesis of limonene is hindered by high energy consumption and pollutant emission. With the advent of biosynthetic technology, microbial biosynthesis has been developed as a new method of producing limonene, which has the advantages of low energy consumption, environmental protection, and sustainability. However, microbial biosynthesis of limonene also has some problems such as low yield and low efficiency, which makes it challenging to commercialize microbial limonene production. Therefore, constructing an efficient microbial cell factory for heterologous biosynthesis of limonene to replace traditional plant extraction methods will have great economic and social benefits. Here, we critically review the recent achievements in engineering yeast for limonene biosynthesis, and describe the synthetic strategies for limonene overproduction in microbial chassis by metabolic engineering and synthetic biology. We also discuss the feasible strategies for relieving limonene toxicity to the host cells and enhancing the tolerance of yeast to limonene.

Key words: metabolic engineering; Saccharomyces cerevisiae; limonene; synthetic strategies