Determination of antimicrobial activity of two macro algae extracts

Abstract

In this study, antimicrobial activity of the possibility of using ethanol extracts obtained from seaweeds Ulva rigida and Gracilaria verrucosa were examined. U. rigida and G. verrucosa were collected from the Coast of Inciraltı (Izmir, Turkey). In the laboratory, the samples were cleaned by rinsing with tap and distilled water, and then dried at 40 °C for 24 hours. Dried and pulverized seaweed samples (10 g) were weighed into an amber Erlenmeyer flask, and 200 ml of 95% (v/v) ethanol was added. The mixture was shaken and extracted in a water bath shaker at temperatures of 30 °C, 45 °C and 60 °C for 30 min. The extracts were filtered, and ethanol was removed using a rotary evaporator to obtain extracts. Ethanolic extracts of U. rigida and G. verrucosa obtained at different temperatures were evaluated in vitro for antibacterial and antifungal activity on six bacteria ( Bacillus subtilis , Staphylococcus aureus , Enterococcus faecalis , Listeria monocytogenes , Escherichia coli and Pseudomonas aeruginosa ) and two fungi ( Aspergillus brasiliensis and Candida albicans ) using the paper disk agar diffusion method. All extract groups tested were found to have antimicrobial activity against all bacteria and fungi, except for Aspergillus brasiliensis .