The Impact of Low Level X-rays on Biosynthesis of Gold Nanoparticles by Actinobacteria

Gold nanoparticles (GNPs) play an important role in medical, health and environmental applications. All kinds of microorganisms were found to be able to synthesize GNPs. The optimization of laboratory conditions for achieving more economical benefits of mass production has been studied widely.
This study assesses the enhancing effect of low-level X-rays on the biosynthesis of GNPs by Actinomycetals. The isolated Actinomycetes were grown aerobically in MGYP broth media. The harvested bacteria were suspended in 50 mL aqueous HAuCl4 in 12 Erlenmeyer flask. Each group contained4 flasks. 2 groups of samples were irradiated by 30 mGy and 5 mGy X-rays respectively. The third group as control remained without irradiation. The solutions were shake- incubated for 120 h.
After 5 days, the color of first group samples changed from milky to purple, while the color changing occurred after 10 days in the 2nd group samples and the control samples. The UV-vis absorption spectrometry of the irradiated aqueous medium by 30 mGy X-rays confirmed the formation of GNPs.
The findings showed that 30 mGy X-rays stimulated the microorganism to form GNPs in a half time in comparison to other groups.