Bactericidal Activity of Sargassum aquifolium (Turner) C. Agardh against Gram-positive and Gram-negative Biofilm-forming Pathogenic Bacteria

Author(s): Nilushi I. Bamunuarachchi, Fazlurrahman Khan, Young-Mog Kim*

Journal Name: Current Pharmaceutical Biotechnology

Volume 22 , Issue 12 , 2021

Become EABM
Become Reviewer
Call for Editor

Graphical Abstract:


Aim: To study the bactericidal activity of crude ethanolic extract and fractionations obtained from Sargassum aquifolium (Turner) C. Agardh (brown algae) towards Gram-positive bacteria and Gram-negative biofilm-forming human pathogenic bacteria.

Background: The increasing emergence of antibiotic-resistant bacteria in the hospital and community settings has led to the discovery of alternative strategies. Marine organisms are considered as one of the potential sources of diverse bioactive molecules against several biological activities. Hence, the algae, especially the marine brown algae were selected to evaluate its antibacterial activities towards biofilm-forming human pathogenic bacteria.

Objective: To restrain the drug-resistant ability of pathogenic bacteria, we checked the extract of Sargassum aquifolium (Turner) C. Agardh (Phyophyceae) for the concerned bioactive compounds.

Methods: Antibacterial activity towards both Gram-positive and Gram-negative bacteria was evaluated using disk diffusion and broth microdilution assays. Furthermore, the active compound present in the extracts was also identified using Gas-Chromatography-Mass Spectroscopy (GC-MS).

Results: A total of 21 bioactive compounds were identified using GC-MS analysis with different chemical natures. The crude ethanolic extraction was fractionated sequentially according to the eluotropic series from less to extreme polar. The highest zone of inhibition was recorded for ethanolic extract on Listeria monocytogenes with a value of 38.00±0.17 mm and the lowest was 10.67±0.06 mm for ethyl acetate fraction on Pseudomonas aeruginosa. Ethyl acetate fractionate showed a higher effectivity than other fractionations. An MIC value of 256 μg/mL was recorded against Staphylococcus aureus and L. monocytogenes and 512 μg/mL against Escherichia coli and P. aeruginosa. Its ethanolic extract also showed synergism with oxytetracycline on S. aureus, L. monocytogenes, and E. coli. Furthermore, the same extracts also showed synergism with tetracycline on E. coli and with erythromycin on P. aeruginosa.

Conclusion: The present study reports the antibacterial activity of the S. aquifolium (Turner) C. Agardh extracts against human pathogenic bacteria. Furthermore, it also predicts the synergistic activity of selected antibiotic combinations against both selected Gram-positive and Gram-negative pathogenic bacteria.

Keywords: Antibacterial, extraction, fractionations, Sargassum aquifolium (Turner) C. Agardh, synergy, pathogens.

Rights & PermissionsPrintExport Cite as

Article Details

Year: 2021
Published on: 11 January, 2021
Page: [1628 - 1640]
Pages: 13
DOI: 10.2174/1389201022666210111122230
Price: $65

Article Metrics

PDF: 131