Comparative study of antimicrobial activities of some mangrove plants from Sundarban Estuarine Regions of India

Abstract

The study investigated antimicrobial activities in different tissues of four mangrove plants:Avicennia marina (Forsk.) Vierh (Avicenniaceae), Avicennia alba Blume (Avicenniaceae),Clerodendrum inerme Gaertn (Verbenaceae) and Aegiceras corniculatum (L.) Blanco (Myrsinaceae) found in the Sundarban delta regions of West Bengal State, India. Organic solvent extracts obtained from different tissues of these plants were investigated by disc diffusion tests against Gram-positive bacteria (Bacillus subtilis, Bacillus coagulans), Gram-negative bacteria (Escherichia coli, Enterobacter sakazakii and Acinetobacter baumannii) and fungi (Saccharomyces cerevisiae and Termitomyces clypeatus). Results suggested that extracts from various parts of these plants had growth-inhibitory effects on fungus and Gram-positive bacteria. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) values were determined for some of these extracts. The antimicrobial activities were found to be heat stable when the crude extracts were subjected to controlled heat stress. The pH tolerance of the antimicrobial activities was found to be wide ranging with marginal changes in activities at extreme pH. The results suggested that these plants could be exploited in the management of various infectious diseases and their tissue extracts might have roles as pharmaceuticals and preservatives. Key words: Antimicrobial activity, mangrove, Sundarban Estuary, disc diffusion test, heat stability, pH sensitivity.