Advances on the biosynthesis of β-ionone and its key rate-limiting enzyme carotenoid cleavage dioxygenases

β-ionone commonly present in plants is a kind of terpenoid compound with 13 carbon atoms, which has floral fragrance, as well as fruity and woody aroma characteristics. Meanwhile, β-ionone has the activity of inhibiting cancer cell proliferation. Therefore, it is widely used in food industry and care products. Nowadays, natural β-ionone is mainly obtained from plants extraction, but the content of β-ionone in plants is very low, so it is difficult to meet the needs of market. As the rapid development of metabolic engineering and synthetic biology, β-ionone biosynthesis has become the focus of people's research. This review mainly summarizes β-ionone biosynthesis pathway, the key rate-limiting enzyme carotenoid cleavage dioxygenases (CCDs) and the strategies of β-ionone's biosynthesis, and discusses the shortcomings in current research and the future research direction of β-ionone biosynthesis, in order to provide reference for the biosynthesis of β-ionone based on microbial chasis in the future.