Screening of selected marine algae from the coastal Tamil Nadu, South India for antibacterial activity

Abstract

ObjectiveTo screen the antibacterial efficacy of various solvent extracts of marine algae such as Sargassum wightii (S. wightii), Chaetomorpha linum (C. linum) and Padina gymnospora (P. gymnospora) against some selected gram-positive and gram-negative human pathogenic bacteria. MethodsCrude extracts were prepared from the selected marine algae using different solvents namely, hexane, ethyl acetate, acetone and methanol and were tested for their antibacterial activity against human pathogenic bacteria using disc diffusion method. Minimum inhibitory concentration (MIC) was also performed for selected solvent extracts for all the bacterial species. A suitable positive control was also maintained. ResultsAmong the three marine algae screened P. gymnospora and S. wightii were found to be more active than C. linum. It was observed that the acetone extracts of all the three marine algae showed higher inhibitory activity for the selected bacterial species than other solvent extracts. The results revealed that the crude acetone extracts seem to be a good source material in identifying the effective pure antibacterial compound(s) in all the three marine algae and particularly, S. wightii. ConclusionsThe present study showed that the acetone extracts of marine algae such as S. wightii, C. linum and P. gymnospora exhibited good antimicrobial activity. But the acetone extracts of S. wightii possessed highest antibacterial activity than others and so it could be useful in seeking active principles against human pathogenic bacteria.