Evaluation of antibacterial activities in Cladophora glomerata and Enteromorpha intestinalis

Cladophora and Enteromorpha are the filamentous green-algal genuses that have a widespread distribution in Caspian Sea Coast. The aim of this study was to assess the antimicrobial activities of Cladophora and Enteromorpha in South of Caspian Sea. Antibacterial activities of hydroalcoholic extracts of five different gram negative and positive bacteria including Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhimurium, Proteus mirabilis were investigated. The extract was primarily screened for their possible antibacterial effects using disc diffusion methods. The potential antibacterial activities at different concentrations of the extract were elucidated. The extracts of Cladophora and Enteromorpha displayed variable degrees of antimicrobial activities on different bacteria. Among gram positive bacteria the Staphylococcus aureus (with wider zones of inhibition) was found to be more sensitive than Bacillus subtilis and among the gram negative Salmonella enteritidis was found to be more resistant than Pseudomonas aeruginosa in the extract of Cladophora glomerata. On the other hand, in the extract of Cladophora glomerata, the Staphylococcus aureus was found to be more sensitive among gram positive bacteria. In the extract of Enteromorpha intestinalis, the Bacillus subtilis was found to be more sensitive among gram positive bacteria. In general, gram negative bacteria were more resistant than gram positive bacteria. Studies by other researchers revealed the same type of results. The Pseudomonas aeruginosa was found to be the most resistant among all bacteria (without zones of inhibition). Our findings suggest that the possibility of using the Cladophora glomerata and Enteromorpha intestinalis as the novel sources of natural antimicrobial and antioxidant agents for pharmaceutical industries.