1 FR CNRS 3473 IUML Mer-Molécules-Santé (MMS), Université du Maine, Avenue O. Messiaen, Le Mans 72085, France
2 Ifremer, SG2M-LGPMM, Laboratoire de Génétique et de Pathologie des Mollusques Marins, Avenue Mus de Loup, La Tremblade 17390, France
3 Marine Science Department, Kampus FPIK UNDIP, Diponegoro University, Semarang, Indonesia
4 Faculty of Fisheries & Marine Science & LSIH, Brawijaya University, Malang, Indonesia
Keywords : antimicrobial compounds, aquaculture, Haslea ostrearia, marennine, microalgae, Vibrio
Due to their immense biodiversity and their simple culture requirements, microalgae are prime candidates for the development of new "blue technologies", with applications in various fields such as pharmacology, food and feed, cosmetics and biofuels. Numerous studies have evidenced the antimicrobial activities of some microalgae, raw extracts or purified compounds, against viral, fungal or bacterial pathogens. An alternative to chemical antibiotics is necessary because of the increasing resistance of bacteria to these drugs in humans and animals, and the introduction of strict regulation concerning their use. In this context, microalgae were evaluated for their capacity to produce antibacterial compounds against pathogens responsible for infections in aquaculture. Furthermore, the use of microalgae as natural antibiotics in aquaculture could mitigate the risk of antibiotic residues in fish or seafood, which sometimes raises health problems, and also respond to the growing demand of consumers to prevent the presence of chemicals in their food. The regular addition of microalgae in livestock ponds is a common practice as it is known to provide foods with high nutritional values and to improve the quality of the growing medium. Thus, the use of microalgae selected for their antibacterial activities could represent an environment-friendly alternative to chemical antibiotics. The marine diatom Haslea ostrearia is known to synthesize and release the blue-green pigment marennine, responsible for the greening of oysters. Moreover, it has been shown that marennine presents antimicrobial activities1, which could have some application in aquaculture. Indeed, different works have demonstrated in vitro and in vivo the antibacterial activities of this microalga and its pigment against marine pathogens2,3. Research on H. ostrearia / marennine antibacterial activity, especially against bacteria of the genus Vibrio (Gammaproteobacteria), V. aestuarianus, V. coralliilyticus, V. tubiashii, V. alginolyticus and V. parahaemolyticus, is on going, and latest results demonstrates that the activity is strain- and species-dependent.
[1] Gastineau, R., Pouvreau, J. B., Hellio, C., Moranc̀§ais, 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.
[2]Gastineau R., Turcotte F., Pouvreau J.-B., Morançais M., Fleurence J., Winarto E., Semba Prasetiya F., Arsad S., Jaouen P., Babin M., Coiffard L., Couteau C., Bardeau J.-F., Jacquette B., Leignel V., Hardivillier Y., Marcotte I., Bourgougnon N., Tremblay R., Deschênes J-S., Badawy H., Pasetto Davidovich N.A., Hansen G., Dittmer J., Mouget J.-L. 2014. Marennine, promising blue pigments from a widespread Haslea diatom species complex. Marine Drugs 12 : 3161-3189.
[3] Falaise C., François C., Travers M.-A., Morga B., Haure J., Tremblay R., Turcotte F., Pasetto P., Gastineau R., Hardivillier Y., Leignel V., Mouget J.-L. 2016. Antimicrobial compounds from eukaryotic microalgae against human pathogens and diseases in aquaculture. Marine Drugs 14 : 159 doi:10.3390/md14090159
