Investigation of the antifouling constituents from the brown alga <i>Sargassum muticum</i> (Yendo) Fensholt

One of the most promising alternatives to toxic heavy metal-based paints is offered by the development of antifouling coatings in which the active ingredients are compounds naturally occurring in marine organisms and operating as natural antisettlement agents. Sessile marine macroalgae are remarkably free from settlement by fouling organisms. They produce a wide variety of chemically active metabolites in their surroundings, potentially as an aid to protect themselves against other settling organisms. In this study, a dichloromethane extract from the brown seaweed Sargassum muticum was tested in situ and, after 2 months of immersion, showed less fouling organisms on paints in which the extract was included, compared to paints containing only copper after 2 months of immersion. No barnacles or mussels have been observed on the test rack. Identification by NMR and GC/MS of the effective compound revealed the abundance of palmitic acid, a commonly found fatty acid. Pure palmitic acid showed antibacterial activity at 44 A µg mL-1, and also inhibited the growth of the diatom Cylindrotheca closterium at low concentration (EC50 = 45.5 A µg mL-1), and the germination of Ulva lactuca spores at 3 A µg mL-1. No cytotoxicity was highlighted, which is promising in the aim of the development of an environmentally friendly antifouling paint

Isolation of a sulphated polysaccharide from a recently discovered sponge species (Celtodoryx girardae) and determination of its anti-herpetic activity

International audienc

Antioxidant and antibacterial activity of solid-liquid and enzyme-assisted extraction of phenolic compound from three species of tropical Sargassum

International audienc

Antifouling activity of macroalgal extracts on Fragilaria pinnata (Bacillariophyceae): a comparison with Diuron

International audienc

Assessment and monitoring of water quality of the gulf of Morbihan, a littoral ecosystem under high anthropic pressure

International audienceThis field study is intended to propose a global methodology to assess and monitor the water quality of the gulf of Morbihan, a littoral ecosystem under increasing anthropic pressure. To this end, the Locmariaquer site, where Crassostrea gigas is extensively cultivated, was selected to perform a one-year follow-up of tissular glutathione S-transferase and acetylcholinesterase specific activities in this filter feeder organism. Calculation of an integrated index, corresponding to the ratio of the two enzymes activities, allowed to discriminate from the environmental noise, several clusters which could be representative environmental stress, potentially latent pollution. Moreover, the estrogenic activity was assessed in water samples collected at Locmariaquer and other strategic sites of the gulf. The results evidenced a low estrogenic-disrupting compound contamination of waters. Overall, this methodology produced an accurate outlook of a basal state for the gulf and could be developed in the context of a chronic monitoring of this site

Total phenolic content and biological activity of French Sargassum muticum enzymatic hydrolysates

International audienc