Antibiofilm, antimicrobial and cytotoxic activity of extracellular green-synthesized silver nanoparticles by two marine-derived actinomycete

• Published in: RSC advances Vol. 1; no. 17; pp. 1361 - 1367
• Main Authors: Hamed, Ahmed A, Kabary, Hoda, Khedr, Mohamed, Emam, Ahmed N
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 11-03-2020; The Royal Society of Chemistry
• Subjects: Antibiotics; Antiinfectives and antibacterials; Antimicrobial agents; Biofilms; Biosynthesis; Chemistry; Cytotoxicity; Gold; Microorganisms; Nanoparticles; Photon correlation spectroscopy; Reducing agents; Silver; Sterilization
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c9ra11021f

The increase in antibiotic resistance related to microbial biofilms creates an urgent need to search for an alternative and active antimicrobial agent. Recently, nanoparticles have gained considerable attention from scientists due to their potent antimicrobial activity. In the present study, two endosymbiotic actinomycete strains were isolated from marine sponge
Crella cyathophora
by surface sterilization and incubation of sponge pieces on culture media selective for actinobacteria. The culture filtrate extracts, including the bacterial supernatants (F) and cell filtrate (C) of the two actinomycete strains, were used as the reducing agent for the green biosynthesis of silver nanoparticles. The as-prepared silver nanoparticles were characterized using dynamic light scattering, zeta-potential, UV-Vis spectroscopy, and transmission electron microscopy. The average particle size for synthesized silver nanoparticles was about ∼8.66 ± 2 to 35 ± 2 nm with monodisperse spherical-like shapes and polydispersed shapes, respectively. The synthesized silver nanoparticles exhibited significant antimicrobial activity toward pathogenic microbes, especially with
P. aeruginosa
and
E. cloacae
. The effect of silver nanoparticles on the growth curve dynamics of
P. aeruginosa
and
E. cloacae
showed that the slope of the bacterial growth curve continuously decreased with increasing nanoparticle concentration. Moreover, the antibiofilm activity of the silver nanoparticles was measured, and the results showed that the silver nanoparticles displayed high biofilm inhibition activity against
P. aeruginosa
,
B. subtilis
, and
S. aureus
. Furthermore, silver nanoparticles exhibited a low to moderate cytotoxic effect against hepatocellular carcinoma cancerous cells, which reflect its possible use in the biomedical field.
Culture filtrate of 2 actinomycetes extracted from marine sponge
Crella cyathophora
was used for the biosynthesis of AgNPs with a significant anti-microbial and biofilm activity. Also, AgNPs exhibited a low to moderate cytotoxicity against cells.