Optimum conditions for cultivation of the Trailliella phase of Bonnemaisonia hamifera Hariot (Bonnemaisoniales, Rhodophyta), a candidate species for secondary metabolite production

Red algae of the order Bonnemaisoniales produce secondary metabolites that may be used as preservatives for industrial applications. Whereas species of Asparagopsis are cultured on a large scale for this purpose, no similar applications have been attempted for Bonnemaisonia species, despite evidence suggesting a similar potential for production of valuable natural products. Optimal conditions for growth of the Trailliella phase of Bonnemaisonia hamifera were assessed experimentally under controlled conditions. Several factors (temperature, photon irradiance, daylength, aeration, culture medium, concentration of nutrients) were tested. Optimal conditions for biomass production in Trailliella are represented by a combination of temperatures of 15-20°C, photon irradiances of 20-30 μmol photons m^-2 s ^-1 and long daylenghts (16:8 h L:D). Quarter-strength von Stosch medium proved to be the best of those tested; aeration contributed also to a higher biomass production. Any attempts of large-scale cultivation should be performed therefore under similar conditions. The growth responses indicate that strains maintained in long-term culture collections can be successfully used for largescale production.