|
Antibacterial activity of an ethanolic premix extract of brown macroalgae against marine pathogenic bacteria
|
Paria Akbari *   , Fatemeh Khoogar |
|
|
|
Abstract: (173 Views) |
| The growing demand for natural antimicrobial agents has increased interest in alternative compounds to conventional antibiotics in aquaculture. This study investigated the antibacterial activity of an ethanolic extract prepared from a premixed combination of three brown macroalgae, Padina australis, Sargassum ilicifolium, and Stoechospermum marginatum, against selected marine pathogenic bacteria. Algal samples were washed, dried, mixed at equal proportions, powdered, and extracted with ethanol. The extract was evaluated at concentrations of 10, 20, 40, and 80 mg/mL against Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, an acute hepatopancreatic necrosis disease–positive strain (AHPND+), and the probiotic bacterium Lactobacillus plantarum using the agar disk diffusion assay. No inhibitory activity was detected against L. plantarum or V. alginolyticus at any tested concentration. The extract showed weak antibacterial activity against V. parahaemolyticus, V. harveyi, and AHPND+, with inhibition zones significantly smaller than those produced by standard antibiotics (P < 0.05). Among the tested pathogens, V. harveyi exhibited the lowest susceptibility, with a maximum inhibition zone of 3.20 ± 0.20 mm at 80 mg/mL. Although the antibacterial activity of the macroalgal extract was limited compared with conventional antibiotics, the findings indicate that brown macroalgae may represent a potential supplementary source of bioactive compounds for future pharmaceutical and nutraceutical applications. |
|
| Keywords: Brown macroalgae, Ethanolic extract, Marine pathogenic bacteria, Vibrio spp., Disk diffusion assay. |
|
|
Full-Text [PDF 846 kb]
(52 Downloads)
|
Type of Study: Research |
Subject:
Special
Received: 2025/12/28 | Accepted: 2026/03/30 | Published: 2026/05/30
|
|
|
|
|
|
|
| Send email to the article author |
|
|
|
| Add your comments about this article |
|
|
|
