Evaluation of the Antimicrobial activity of aqueous and methanolic extracts of Synechococcus elongatus against pathogenic bacteria

Cyanobacterial secondary metabolites can be a good candidate for inhibition of many n pathogenic bacteria. The general objective of this study was test of antibacterial activity of aqueous and methanolic extract of cyanobacterium Synechococcus elongatus against a number of pathogenic bacteria.In this experimental study, the cyanobacterium Synechococcus elongatus ISC 106 was obtained from the Algal culture collection of research institute of applied science, ACECR, Tehran, Iran. Disk diffusion method was used to study the effect of antimicrobial and broth microdilution method was used to determine the minimum inhibitory concentration (MIC).The results indicated that Methanolic extract of Synechococcus elongatus has no significant effect against tested bacteria. The results also clearly showed that aqueous extract of Synechococcus elongatus have significant antibacterial activity against most pathogenic bacteria; So that maximum antibacterial activity was against Staphylococcus aureus (PTCC 1112) which the average zone diameter around it was 26.33 Millimeters. Minimum inhibitory concentration of aqueous extract against most tested human pathogen bacteria was 125 mg/ml. It is concluded from this study that extracts of Synechococcus elongatus show antimicrobial activity against the human pathogenic bacteria used in the present investigation and antibacterial activity of aqueous extract of Synechococcus elongatus was more than Methanolic extract of Synechococcus elongatus Improvement knowledge of the composition, analysis, and the properties of these cyanobacteria with respect to antimicrobial compounds would assist in efforts for the pharmaceutical application.

Keywords:

Antibacterial activity , Broth microdilution , pathogen bacteria , Synechococcus elongatus