Evaluation of antibacterial activity of some selected green seaweed extracts from Muttam coastal areas, Kanyakumari, Tamil Nadu, India

Abstract

Objective: To investigate the antimicrobial activity of the selected marine green algae Ulva lactuca (U. lactuca), Cheatomorpha linoides and Helimeda macroloba against six strains of Gram-positive bacteria [Staphylococcus aureus (S. aureus), Bacillus subtilis and Lactobacillus acidophilus (L. acidophilus)] and Gram-negative bacteria [Escherichia coli, Pseudomonas aeruginosa (P. aeruginosa) and Proteus mirabilis]. Methods: The selected green seaweed extracts were experimented with four different solvents (acetone, ethanol, methanol and chloroform) against the selected pathogens by using agar disc diffusion method. Results: The maximum activity (7 mm) was observed by the extract of U. lactuca against Proteus mirabilis by using methanol as a solvent and the lowest activity (2 mm) was recorded by the extract of U. lactuca against L. acidophilus by using chloroform as a solvent and ethanol extract against P. aeruginosa. The lowest activity (2 mm) was seen in the extract of Cheatomorpha linoides by using ethanol and methanol as a solvent against S. aureus. In Helimeda macroloba extract, the lowest activity was recorded against Escherichia coli by using chloroform as a solvent. The microbial strains S. aureus, P. aeruginosa, Bacillus subtilis and L. acidophilus were resistant to the chloroform and methanol of all selected seaweeds. Conclusions: Further study should be needed to identify the prime compound which is responsible for the activity against the selected pathogens especially those causing the human diseases.