Red and brown seaweeds differently inhibit colonization by epiphytic bacteria
Résumé
The inhibition of bacterial colonization by seaweeds belonging to the Florideophyceae and Phaeophyceae classes, collected along the Brittany coast (France), was evaluated using two epiphytic bacteria. Organic and aqueous extracts were screened for their potential to prevent colonization by the bacterium Zobellia galactanivorans and the commensal Pseudoalteromonas sp. 3J6. Among the 14 species evaluated in a colorimetric 96-well bioassay, the methanolic extracts of 5 Florideophyceae showed the highest activities on Z. galactanivorans but revealed no activity on Pseudoalteromonas 3J6. These results suggest that unknown polar compounds may control adhesion and/or biofilm development of epiphytic bacteria on seaweed surfaces.