Actinomycetes mediated synthesis of gold nanoparticles from the culture supernatant of Streptomyces griseoruber with special reference to catalytic activity.

Biogenic synthesis of nanoparticles has received a tremendous attention from the past few decades. The significant progress in the field of nanotechnology has resulted in a cost-effective and eco-friendly process for nanoparticle synthesis. In the present study, the extracellular synthesis of gold nanoparticles was carried out using culture supernatant of Streptomyces griseoruber, actinomycetes isolated from the soil. Bioreduction of gold nanoparticles was confirmed by UV-visible spectrophotometer that showed the peak between 520 and 550 nm. The crystalline nature and mean size of the GNPs were confirmed using XRD. FTIR revealed the possible functional group that could be useful in immobilisation and stabilisation of GNPs. Size and distribution of the biosynthesized GNPs were analysed by HR-TEM that showed the formation of GNPs in the range of 5-50 nm. The synthesised GNPs showed good catalytic activity for the degradation of methylene blue. The study shows the rapid and eco-friendly synthesis of GNPs from Streptomyces griseoruber, and this is the first report on the catalytic activity of GNPs from actinomycetes so far.