Biochemical properties and culture optimization of Leathesia marina (Phaeophyceae)

In recent years, interest in the chemical composition of algae, and the art of farming them, has grown due to their nutritional and health benefits. Species of Leathesia collected from nature have pharmaceutical properties, such as antitumor, antiviral, antioxidant and cytotoxic activity. Accordingly, their culture under controlled conditions is fundamental for the sustainable maintenance of natural populations. In this study, the biochemical constituents of L. marina: organic matter, alginate, total carbohydrate, protein content, pigments, polyphenols, antioxidant activity and the composition of elements, were analyzed, and the best culture conditions, such as seawater temperature and nutrient concentrations for the sporophytic and gametophytic phases, were determined. In that way, we evaluated the best fit of the abiotic conditions for their growth, controlling the fertility on the gametophyte and their long-term storage. The biochemical composition of the L. marina sporophyte varied according to the extraction method used. L. marina showed a relatively low carbohydrate and protein content, but a high polyphenol content and antioxidant activity. In the culture experiments, zygote and spore densities were significantly influenced by nutrient concentrations. The best survival conditions for gametophytes and sporophytes were at 8 °C and at 1 PES; however the growth of the sporophytes was greater than that of the gametophytes. The gametophytes could be maintained in latency under controlled conditions for 18 months. Gametogenesis suppression was observed at 8 °C in a 12:12 h L/D regime. In this study, we emphasize the need to know about both the biochemical composition of L. marina for industrial use and the optimal conditions for L. marina culture in order to establish an adequate controlled population management.