Endophytic fungus Alternaria spp isolated from Rauvolfia tetraphylla root arbitrate synthesis of gold nanoparticles and evaluation of their antibacterial, antioxidant and antimitotic activities

B Hemashekhar, C P Chandrappa, M Govindappa and N Chandrashekar

Abstract

In our present study, we have developed a new, endophytic mediated technique for the synthesis of gold nanoparticles (AuNPs) from the endophytic fungus Alternaria spp. extract isolated from Rauvolfia tetraphylla root. The synthesized AuNPs were characterized using Ultraviolet-visible spectroscopy (UV–vis), Energy Dispersive x-ray Spectroscopy (EDX) and Transmission Electron Microscopy (TEM) thoroughly. It has been confirmed as the variable shapes accompanied average particle size of 28 nm. Further, the characterized AuNPs were screened for their antibacterial activity against Gram positive bacteria Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia and Gram negative bacterium Staphylococcus aureus. The synthesized AuNPs were tested for antioxidant, antibacterial and antimitotic activities. The AuNPs showed considerable antibacterial, antioxidant and antimitotic activities. It is a novel method to report the synthesis of AuNPs using Rauvolfia tetraphylla based endophytic extract as a reducing agent.