Evaluation of in vitro antibacterial property of seaweeds of southeast coast of India

The in vitro antibacterial activities of seaweeds belong to Chlorophyceae (Caulerpa racemosa and Ulva lactuca), Rhodophyceae (Gracillaria folifera and Hypneme muciformis) and Phaeophyceae (Sargassum myricocystum, Sargassum tenneerimum and Padina tetrastomatica) were studied against both Gram-negative and Gram-positive pathogenic bacteria. Methanolic extracts of all seaweed extracts tested in the present study exhibited broad spectrum of antibacterial activity. Chlorophyceae members showed high antibacterial activity than other members of the algae tested in the present investigation. Escherchia coli alone resistant to all the seaweed extracts except S. teneerimum. Results of the present study confirmed the potential use of seaweed extracts as a source of antibacterial compounds.