Determination of antimicrobial, antioxidant properties and polyphenolic compounds of seaweeds originated from south coast region of Maharashtra

The present study demonstrates the antimicrobial, polyphenolic compounds and antioxidant potential of brown marine algae collected from the south coast region of Maharashtra. The methanolic extracts were tested against gram positive, gram negative bacteria in an attempt to be used as an alternative to commonly used antibiotics. Both brown seaweed species Sargassum wightii and Ascophyllum nodosum methanolic extracts were found to be active against gram positive as well as gram negative bacteria. Ascophyllum nodosum methanolic extract gave the highest inhibitory activity against Klebsiella sp. The present work shows a comparable therapeutic potency of tested seaweed members Sargassum and Ascophyllum extracts in treating human microbial pathogens to synthetic chemical antibiotics. A remarkable higher antioxidant DPPH free radical scavenging effect was recorded with Ascophyllum nodosum extract compared to Sargassum sp. Total flavonoid and phenol contents were determined by colorimetric methods using querecitin and gallic acid standards. FTIR Infrared Spectrometer analysis together with the high performance liquid chromatography provided a detailed description of possible functional constituents and major chemical components present in the marine macroalgae particularly in brown seaweeds to be mainly of phenolic nature to which the potent antimicrobial activity is being attributed.