Microalgal fatty acid methyl ester a new source of bioactive compounds with antimicrobial activity

Abstract

ObjectiveTo evaluate fatty acid composition and the antimicrobial activity of the major fraction of fatty acid methyl ester (FAME) extracts from three microalgae collected from freshwater lakes in Theni District, Tamil Nadu, India. MethodsAntimicrobial study was carried out by well diffusion method against bacterial as well as fungal pathogens such as Escherichia coli, Staphylococcus aureus, Enterobacter sp., Klebsiella sp., Salmonella typhi, Fusarium sp., Cryptococcus sp., Candida sp., and Aspergillus niger and Aspergillus flavus. The FAME profiles were determined through gas chromatography with a flame ionization detector. ResultsThe FAME was found to be radial effective in inhibiting the radial growth of both bacterial and fungal pathogens. The FAME extracts exhibited the antibacterial activity against three clinical pathogens, namely, Escherichia coli, Salmonella typhi and Enterobacter sp. with the maximum zone of inhibition of 12.0 mm, 12.0 mm and 11.0 mm, respectively. The FAME showed moderate antifungal activity against Cryptococcus sp. (11.8 mm), Aspergillus niger (10.5 mm), Candida sp. (11.8 mm) and Fusarium sp. (10.4 mm). Gas chromatography-flame ionization detector analysis revealed about 30 different FAMEs. ConclusionsWe assume that the observed antimicrobial potency may be due to the abundance of erucic acid methyl ester (C22:0), arachidic acid methyl ester (C20:0), palmitic acid methyl ester (C16:0), cis-11-eicosenoicmethyl ester (C20:1), cis-11, 14-eicosadienoic acid methyl ester (C20:2) and linolenic acid methyl ester (C18:3) in FAMEs which appears to be promising to treat microbial diseases.