ANTIBACTERIAL ACTIVITY OF VARIOUS SOLVENT EXTRACTS OF SPIRULINA PLATENSIS AGAINST HUMAN PATHOGENS

Abstract

Background: Spirulina has been used as human food supplement over the last century. It contains high protein content, vitamins (A, D, E, K and B complex vitamins), beta-carotene, manganese, zinc, copper, iron, selenium, and gamma linolenic acid. Numerous studies reported that Spirulina contains biological properties such as immunomodulation, antioxidant, anticancer, antimicrobial and probiotic effects. Aim: In the present study, phytochemical analysis and in vitro antibacterial activity of four different solvent extracts (methanol, acetone, chloroform and hexane) of Spirulina platensis was examined. Methods: agar well diffusion technique and paper disc diffusion technique were used to analyse the antimicrobial against human bacterial pathogens viz., Escherichia coli, Salmonella typhi, Proteus mirabilis, Vibrio vulnificus and Cellulomonas cellulans. Results: Results cleared that methanol and chloroform extracts of Spirulina platensis showed maximum zone of inhibition against E.coli followed by Cellulomonas cellulans and Proteus mirabilis at 100 µg concentration. Acetone extracts showed moderate biological activity against all tested organisms and least activity was recorded in hexane extracts at 10 µg concentrations. Presence of phytochemical compounds such as protein, carbohydrates, flavonoids, phenols, terpenoids and steroids exhibits the relation to the antimicrobial activity of Spirulina platensis against human pathogens. Conclusion: nutritional composition and antimicrobial activity analyses of our present study helps in increasing the importance of utilising Spirulina platensis.

Key words: antimicrobial activity, phytochemical compounds, human pathogens.