Bioactive metabolites and extracellular vesicles from the marine chlorophyte genus Tetraselmis: Review

Microalgal biotechnology offers sustainable applications that align with the principles of the circular bioeconomy, providing innovative and resource-efficient solutions to help achieve the United Nations' Sustainable Development Goals. Within this framework, the marine chlorophyte genus Tetraselmis is attracting increasing attention for its potential in biotechnology and biomedicine. As facultative mixotrophs, Tetraselmis species exhibit metabolic flexibility and high tolerance to abiotic stresses, enabling the efficient biosynthesis of a wide range of bioactive compounds, including polyunsaturated fatty acids (PUFAs), carotenoids, tocopherols, and phenolic compounds. These compounds exhibit a broad spectrum of beneficial biological activities, such as antioxidant, anti-inflammatory, immune-modulating, antibacterial, antiviral, and anticancer properties, making Tetraselmis species valuable resources for functional foods, nutraceuticals, cosmetics, aquaculture, and pharmaceuticals. Furthermore, potential applications have been further supported by the European Union's approval of T. chuii for human consumption under the novel food regulatory framework. Additionally, extracellular vesicles (EVs) derived from T. chuii are among the most well-characterised microalgal-derived EVs. These EVs have been shown to reduce oxidative stress, modulate inflammatory pathways, and exhibit low toxicity and high biocompatibility in both human cell lines and in vivo models. Given their natural bioactive composition, these EVs offer promising potential as an innovative platform for drug delivery. This review explores the metabolic flexibility, bioactive compound production, and the therapeutic potential of Tetraselmis species and their EVs, highlighting their diverse applications in biotechnology and biomedicine. The integration of emerging interdisciplinary tools such as artificial intelligence (AI) and synthetic biology presents new opportunities to optimise cultivation strategies, enhance EV yield and functionality, and enable the engineering of strain-specific traits. These advances are expected to accelerate the development of precision Tetraselmis-based applications across biomedicine, aquaculture, and environmental sustainability, reinforcing their potential for industrial-scale adoption within next-generation biomanufacturing platforms.