Mycobiology.  2012 Mar;40(1):27-34.

Antimicrobial and Synergistic Effects of Silver Nanoparticles Synthesized Using Soil Fungi of High Altitudes of Eastern Himalaya

• Devi LS
• Joshi SR

Abstract

Fifty three fungi isolated from soils of different microhabitats of eastern Himalayan range (3,400~3,600 msl) were screened for mycosynthesis of silver nanaoparticles (AgNPs) and their efficacy as antimicrobials were assessed in combination with commonly used antibiotics. Three isolates Aspergillus terreus SP5, Paecilomyces lilacinus SF1 and Fusarium sp. MP5 identified based on morphological and 18S rRNA gene sequences were found to synthesize AgNPs. These nanoparticles were characterized by visual observation followed by UV-visible spectrophotometric analysis. The AgNPs synthesized by Aspergillus terreus SP5, Paecilomyces lilacinus SF1 and Fusarium sp. MP5 showed absorbance maxima at 412, 419, and 421 nm respectively in the visible region. Transmission electron microscopy micrograph showed formation of spherical AgNPs of 5~50 nm size. The antimicrobial activity of the mycosynthesized nanoparticles were investigated alone and in combination with commonly used antibiotics for analysis of growth inhibition zone against test organisms, namely, Staphylococcus aureus MTCC96, Streptococcus pyogenes MTCC1925, Salmonella enterica MTCC735 and Enterococcus faecalis MTCC2729. The mycosynthesized nanoparticles showed potent antibacterial activity and interestingly their syngergistic effect with erythromycin, methicillin, chloramphenicol and ciprofloxacin was significantly higher as compared to inhibitions by AgNPs alone. The present study indicates that silver nanoparticles synthesized using soil borne indigenous fungus of high altitudes show considerable antimicrobial activity, deserving further investigation for potential applications.

Keyword

Antibiotics; Antimicrobial activity; Fungal isolates; High altitudes; Silver nanoparticles; Synergy

MeSH Terms

Altitude
Anti-Bacterial Agents
Aspergillus
Chloramphenicol
Ciprofloxacin
Enterococcus faecalis
Erythromycin
Fungi
Fusarium
Genes, rRNA
Methicillin
Microscopy, Electron, Transmission
Nanoparticles
Paecilomyces
Salmonella enterica
Silver
Soil
Staphylococcus aureus
Streptococcus pyogenes
Anti-Bacterial Agents
Chloramphenicol
Ciprofloxacin
Erythromycin
Methicillin
Silver
Soil