Potential antibacterial activity of crude extracts and silver nanoparticles synthesized from Sargassum wightii

Abstract

The present work investigates the antibacterial activity of silver nanoparticles (Ag-NPs) synthesized by biological method using Sargassum wightii. The fresh live seaweed was collected from the Mandapam coast of Tamilnadu, India. Solvent extract was prepared using acetone, petroleum ether and methanol. Aqueous extract of the seaweed was also used for the synthesis of silver Ag-NPs. Seaweed extract is used as a reducing agent of 2mM silver nitrate solution for the synthesis of Ag-NPs. Periodical monitoring of reaction mixture was done using UV-vis spectroscopy at 300-750 nm. The scanning electron microscopy (SEM) of the sample confirms the presence of Ag-NPs. The antibacterial activity of solvent extract was done by Minimal inhibitory concentration (MIC) assay. The methanol extract of the seaweed at a concentration of 250µg/ml exhibited potent antimicrobial activity against the test microorganism. The zone of inhibition ranging from 8-14 mm was observed with different extracts. The antibacterial activity of the synthesized Ag-NPs against the organism was also done by MIC test. The MIC of Ag-NPs was found to be 130µg/ml for all pathogenic microorganisms selected for the study. The zone of inhibition against Bacillus cereus, Bacillus anhtracis, Staphylococcus aureus and Vibrio alginoyticus were found to be 10, 8, 10 and 9 mm, respectively. The synthesized Ag-NPs exhibited significant antimicrobial activity against the selected microorganisms than the solvent extract of seaweed.DOI: http://dx.doi.org/10.3329/icpj.v3i10.20337 International Current Pharmaceutical Journal, September 2014, 3(10): 322-325

Sargassum, Gracilaria and Ulva Exhibit Positive Antimicrobial Activity against Human Pathogens

“…In our results, ZOI formed by S. wightii methanol extracts against S. aureus was the highest, which was 2.9-fold higher than previously observed for S. wightii methanol extract from Mandapam [31] and agreed that methanol extract for S. wightii against S. aureus was better than other solvents [42]. Though, S. wightii butanol and ethyl acetate extracts showed considerable bioactivity against both S. aureus, P. aeruginosa and E. coli in our results, S. wightii methanol extracts showed no bioactivity against E. coli, which agreed with the findings for Sargassum vulgare with no activity [44] and disagreed with observations for S. wightii [45].…”

“…However, methanol extracts of both U. reticulata and U. lactuca were effective against human pathogens [30]. In case of Sargassum wightii methanol extracts were effective against S. aureus [31] and against E. coli, and P. aeruginosa [32], whereas ethyl acetate extracts of S. wightii were only effective against Bacillus subtilis [33].…”

Valorisation of the Invasive Macroalgae Undaria pinnatifida (Harvey) Suringar for the Green Synthesis of Gold and Silver Nanoparticles with Antimicrobial and Antioxidant Potential

“…Comparing the results of the present study with silver and gold nanoparticles produced with extracts of the brown seaweeds Cystoseira tamariscifolia and Cystoseira baccata, the MIC values for the non-biofilm-producing bacteria are at much lower concentrations with the biogenic U. pinnatifida nanoparticles [48]. Other authors reported that silver nanoparticles synthesized in Sargassum wightii (average size 48.78 nm) were toxic to S. aureus at a MIC of 130 µg/mL [49], while particles produced in Turbinaria conoides (up to 80 nm) showed a MIC of 64 and 8 µg/mL against P. aeruginosa and S. aureus, respectively [50]. Gold nanoparticles produced in Sargassum illicifolium (20-25 nm) and in Sargassum muticum (10.4 ± 1.2 nm) registered a MIC in planktonic S. aureus of 48 and 39.5 µg/mL, respectively [42,51].…”

Plasmon assisted 3D microstructuring of gold nanoparticle-doped polymers

“…Research aiming to combine 3DLL and biomedicine is currently gathering a great deal of interest and shows promising results in creating 3D scaffolds for stem cell growth [21,42]. It was shown that nanoparticles in general can perform many different roles in medicine, such as antibacterial agents [54], helping with magnetic fluid hyperthermia [55] or use for advanced drug or even gene delivery [56]. The inclusion of nanoparticles in polymer structures can lead to active medical implants that have desired properties and biofunctionalisation given by the nanoparticles or even act as a nanoparticle delivery system if the polymer is biodegradable [57].…”