1 FR CNRS 3473 IUML, Mer-Molécules-Santé (MMS), Université du Maine, Ave O. Messiaen, 72085 Le Mans cedex 9, France.
2 School of Earth and Ocean and Sciences, Cardiff University, Cardiff, UK.
Keywords : aquaculture, biodiversity, Haslea, H2020 RISE, marennine
The genus Haslea is a taxonomic unit of pennate diatoms defined by R. Simonsen in 19741. Regarding diatom morphology, the genus Haslea refers to fusiform or lanceolate cells with a frustule made of two valves, each presenting straight striae, both transversally (transapical striae) and longitudinally (apical striae). Characteristically, Haslea frustule valves present a totally different aspect when comparing their external and internal surfaces. The former presents continuous longitudinal fissures, the latter is perforated by areolar, square to rectangular openings, forming grate-like bars. These two layers are assembled in a typical sandwich-like structure. The genus Haslea type species is H. ostrearia, a tychopelagic/benthic/epiphyte organism that produces marennine, a water-soluble blue pigment responsible for the greening of oysters in Western France. Marennine is also a bioactive molecule, and blue Haslea have a high potential for use in existing oyster farming, the production of pigments and bioactive compounds with natural antibacterial or cytostatic properties, and novel applications as an industrial colouring agent2. Moreover, like for many diatoms, silica skeleton wastes from frustules could be exploited as inorganic “biocharges” in the formulation of new elastomeric materials. Recently, a H2020 project has been funded to explore the genus Haslea, and to characterize this marine bioresource for blue biotechnology applications in aquaculture, cosmetics and possibly food and health industry, the programme GHaNA (The genus Haslea, new resource for biotechnology and aquaculture). The project GHaNA is a collaborative research program based on a partnership between 20 academic and two non-academic partners, having complementary expertise and resources, facilitating interdisciplinary research and staff exchange and training. It will determine the biological and chemical diversity of Haslea diatoms and will develop mass-scale production processes, to achieve viable industrial production of biomass and associated high-value compounds, including terpenoids3, marennine-like pigments, lipids and silica skeletons. This will be achieved through fundamental and applied-oriented research to isolate fast-growing strains of Haslea, optimising their growth environment and cultivation system (ad hoc photobioreactors) to increase marennine and other high-value compound productivity, to develop blue biotechnology specifically applied to benthic microalgae (biorefinery approach), and to explore the potential for industrial exploitation of colouring and bioactive compounds through commercial activities of aquaculture, food, cosmetics and health.
[1] Simonsen, R. (1974). The diatom plankton of the Indian Ocean expedition of RV “Meteor”. “Meteor” Forschungsergebnisse, Reihe D, 19: 46–49
[2] Gastineau, R., Pouvreau, J. B., Hellio, C., Morançais, M., Fleurence, J., Gaudin, P., et al. (2012). Biological activities of purified marennine, the blue pigment produced by the diatom Haslea ostrearia and responsible for the greening of oysters. Journal of Agriculture and Food Chemistry, 60, 3599–3605.
[3] Rowland, S. J., Belt, S.T.,Wraige, E. G., Massé, G., Roussakis, C., & Robert, J.-M. (2001). Effects of temperature on of polyunsaturation in cytostatic lipids of Haslea ostrearia. Phy- tochemistry, 56, 597–602.
