Screening of phytochemical profile and antibacterial activity of various solvent extracts of marine algae Sargassum swartzii

The present study investigates phytochemical screening and antibacterial efficacy of various solvent extracts of marine algae such as Sargassum swartzii against some selected human and fish pathogenic bacteria. The brown seaweed Sargassum swartzii was collected from Kudankulam, Tirunelveli district, Tamil Nadu, India. Soxhlet extraction method was used to get the extracts of different solvents like aqueous, ethanol, methanol, acetone and were tested for their qualitative phytochemical screening using common standard tests. Quantitative phytochemical analysis such as total phenolic content and total flavonoid content of S. swartzii and antibacterial activity against human pathogens viz., Escherichia coli, Pseudomonas aeruginosa and Stephylococcus aureus and fish pathogens viz., Aeromonas hydrophila and Vibrio vulnificus bacteria using disc diffusion methods. Preliminary phytochemical screening of sixteen different chemical compounds were carried out. The maximum biochemical compounds were present in the ethanol extract and the minimum compounds were present in aqueous extract. The ethanol extract was significantly higher in phenolic content (15.35 ±2.61 mg of GAE/g) and the methanol extract was significantly higher in flavonoides content (26.92±7.14 mg of QE/g). In human pathogen the highest antibacterial activity was present in Pseudomonas aeruginosa (18.00±0.00mm) and the fish pathogen was significantly higher in Aeromonas hydrophila. The present study showed that the ethanol extract of marine brown seaweed Sargassum swartzii contains bio active constituents with highest antibacterial activity against human and fish pathogen.