Seasonal variation of antibacterial activity of the brown alga Padina pavonica (l) Thivy collected from northern coast of Tunisia.
Keywords:
Molecular structure, Biological control, Moisture, Evaporation, Incubation, Antibiotics, Colonies, Thermometers, Dry weight, Enzymatic activity, Chemical extraction, Seasonal variations, Bacteria, Algal culture, Pathogenic bacteria, Temperature, Solvents, Drying, Mollusc culture, Enzymes, Pathogens, Toxicity, Strains, Processing fishery products, Epibionts, Seasons, Padina, Padina pavonica, Marine, MED, Tunisia, North CoastAbstract
Variations in antibacterial activities of the brown alga Padina pavonica collected from the Northern coast of Tunisia: Cap Zebib, were evaluated monthly during one year period (from July 2006 to June 2007). Dichloromethane and dichloromethane/methanol crude extracts of the alga were screened against a panel of pathogenic bacteria and Padina surface-associated bacteria. Crude extracts of the alga collected in summer showed the largest spectrum of activity against both Gram+ and Gram- pathogens whereas extracts collected in spring exhibited a varying amount of activity especially against Gram+ bacteria whereas and those collected in winter did not exhibit any activity against tested bacteria. From the two organic solvents used for alga extraction, the most suitable was the dichloromethane /methanol with better effectiveness on bacteria. Effect of the alga extracts, were very weak against associated bacteria. This selective toxicity may be important for theses epibionts since, it should maintains a chemical defense against microbial pathogens. The present results highlight the possible use of Padina pavonica as source of antibacterial compounds mainly provided in warm seasons from the alga.
