Résumé:
Marine macroalgae and their associated microorganisms are increasingly recognized as
valuable sources of natural bioactive compounds. This study investigates the antibacterial
potential of various algal specimens and the microbial communities naturally associated with
them, collected from diverse aquatic environments in northeastern Algeria. The work
combines morphological analysis, microbiological isolation, and antimicrobial assays to
evaluate their biological activity.
Algal samples were cultivated and analyzed under controlled laboratory conditions.
Bacterial strains were isolated from the surface of algae and tested for their ability to inhibit
selected pathogenic microorganisms. In addition, the direct antibacterial effect of the algal
material itself was assessed using standardized in vitro techniques.
The results demonstrated that both the algae and their associated bacteria possess
significant antibacterial properties. Several isolates produced measurable zones of inhibition,
while algal extracts also exhibited inhibitory effects against common human pathogens. These
findings confirm the presence of bioactive substances and suggest a potential synergistic
interaction between algae and their microbiota. Environmental factors such as salinity and
nutrient conditions appeared to influence the expression of these bioactivities.
This study provides new insight into the antimicrobial potential of algae–bacteria
associations and reinforces the value of marine biodiversity as a source for natural therapeutic
agents. It also highlights the ecological and biotechnological importance of studying aquatic
microbial communities in underexplored regions.
