Research Progress on Structure, Bioactivity, Biosynthesis, Extraction and Industrialization of C₅₀ Carotenoids

C₅₀ carotenoids are predominantly derived from microorganisms, featuring a conjugated polyene chain as the core skeleton. Their structural diversity arises from modifications by functional groups including hydroxyl and ketone moieties. Currently, research on their biosynthesis remains limited, with lycopene widely recognized as the primary precursor. As a novel class of natural carotenoids, C₅₀ carotenoids demonstrate significantly higher antioxidant activity compared to common C₄₀ carotenoids. Moreover, they possess multiple biological properties, including anti-inflammatory, antitumor, antimicrobial, antiviral, and antihemolytic activities. These attributes indicate broad application potential in fields such as food, aquaculture, and biomedicine. However, the large-scale production and industrial application of C₅₀ carotenoids face several challenges, including low yield, high production costs, underdeveloped extraction and purification techniques, and insufficient stability studies. To address these issues, future research directions are proposed, involving the construction of high-yield strains via synthetic biology to enhance bacterioruberin production, the exploration of open fermentation strategies to reduce costs, the development of green extraction and purification technologies to improve efficiency, and the optimization of carrier systems and storage conditions to enhance stability and bioavailability. These efforts are expected to provide a theoretical foundation for the efficient development and multi-scenario utilization of novel carotenoid resources.