Isolation, biosynthesis and antimicrobial activity of gold nanoparticles produced with extracts of Anabaena spiroides

Bioprocess Biosyst Eng. 2021 Aug;44(8):1617-1626. doi: 10.1007/s00449-021-02544-4. Epub 2021 Mar 11.

Abstract

Multidrug-resistant (MDR) pathogenic bacteria have become dangerous in bringing sporadic outbreaks in public health and nosocomial spreads from the addition of antibacterials/antibiotics continually. Obviously, the pharmacy world is in search of antibacterials that would be invincible by the evolved bacteria. Green synthesis of gold-nanoparticles (AuNps) was focused on the use of aqueous chloroauric acid (HAuCl4) and cell-free aqueous extract of the N2-fixing cyanobacterium (blue-green alga) Anabaena spiroides collected from a brackish-water, Bay of Bengal at Puri, Odisha; green-synthesized AuNps could be used as antibacterials against MDR bacteria. The synthesized AuNps were subjected to the following characterizations, UV-Vis spectrophotometry, SEM-EDX, XRD and ART-FTIR analysis. An absorption peak at 538 nm by UV-Vis spectrophotometry and the FTIR analysis confirmed the presence of AuNps. A. spiroides-AuNps were monitored for antibacterial activities against MDR pathogenic bacterial strains isolated from clinical samples, namely, Klebsiella oxytoca, MRSA and Streptococcus pyogenes, in vitro; the individual antibiograms of those bacteria were known. The recorded MIC dose values were 25, 20 and 30 mg A. spiroides-AuNps (As-AuNps) against K. oxytoca, MRSA and S. pyogenes, in vitro, respectively. Thus, As-AuNps bear promises as possible antibacterials, in future.

Keywords: Anabaena spiroides; Antibacterial activity; Blue-green alga; Cyanobacterium; Gold nanoparticles.

MeSH terms

  • Anti-Bacterial Agents
  • Anti-Infective Agents / pharmacology*
  • Biomass
  • Chlorides / chemistry
  • Cyanobacteria / metabolism*
  • Drug Resistance, Multiple*
  • Enterococcus faecalis
  • Gold / chemistry*
  • Gold Compounds / chemistry
  • Klebsiella oxytoca
  • Metal Nanoparticles / chemistry*
  • Methicillin-Resistant Staphylococcus aureus
  • Microbial Sensitivity Tests*
  • Microscopy, Electron, Scanning
  • RNA, Ribosomal, 16S / metabolism
  • Spectrophotometry, Ultraviolet
  • Spectroscopy, Fourier Transform Infrared
  • Streptococcus pyogenes
  • X-Ray Diffraction

Substances

  • Anti-Bacterial Agents
  • Anti-Infective Agents
  • Chlorides
  • Gold Compounds
  • RNA, Ribosomal, 16S
  • Gold
  • gold tetrachloride, acid

Supplementary concepts

  • Dolichospermum spiroides

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