Seaweed and antibiotics

One hundred and fifty marine algae were tested for antibiotic activity against four laboratory indicator baceteria. Sixty-six of them showed antimicrobial activity against Staphylococcus aureus or other common laboratory microbes. Also bacteria isolated from the sea were strongly inhibited by a few algae. Far over one hundred seaweed species are known to contain antibiotic substances, even when those with faint effect are first sorted out. Do these figures entitle us to hope for new substitutes for pencillin from algae? At present the answer has to be in the negative or at least hesitant; actually none of the many antibiotic substances from seaweeds is pharmaceutically utilized. On the other hand investigations into antibiotic activity of marine plants are not usually initiated in search for new drugs but from an interest in the nature of competition. In an aqueous surrounding, the organisms must have an active defence against bacteria and fungi, and against each other to keep their living space free from epiphytes as necessary and to keep their living space free from competitors. Each species has its own means in the chemical warfare on rocks and in crevices. Consequently the distribution of antibiotic activity is universal in the world of algae. Antibacterial activity is as common in algae from tropical seas as in those from varm or cold temperate waters. Within genera known for wide distribution and rich occurrencies antibacterial have been found amon the green algae.