Myco-Fabricated Gold Nanoparticles from Aspergillus tamarii MTCC5152, its Characterization and Dye Biodegradation

Abstract

This work was initiated to investigate the myco-fabrication of gold nanoparticles (AuNPs) using a fungal strain, Aspergillus tamarii 5152 (A. tamarii MTCC 5152). The biosynthesized gold nanoparticles were characterized by visual observation, and using UV-Vis and Fourier transform infrared spectroscopy (FTIR) spectroscopy, Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Zeta-potential, Dynamic light scattering (DLS) and Scanning Electron Microscopy (SEM) analyses. NADH-dependent cofactor analysis and photocatalysis assays were carried out for Nicotinamide adenine dinucleotide (NADH)-dependent AuNPs biosynthesis and dye degradation ability. A maximum surface plasmon resonance peak for the AuNPs was recorded at 535 nm, followed by the identification of protein capping effect of the extract by FTIR spectroscopy. The average size (Z) of the nanoparticles observed was 39.15 nm, while SEM images showed crystallized rod-shaped structures ranging from 55-91 nm. A negative zeta potential of 10.5 mV showed repulsion between the nanoparticles, which indicates the stabilizing power of the fungal extract. Further, it was observed that NADH acts as a cofactor for the nanoparticle biosynthesis. The AuNPs were found to degrade crystal violet dye by 63%. From this study, it can be understood that the process of fungal mediated biosynthesis of AuNPs by A. tamarii MTCC 5152 is simple, less expensive, and could be utilized for bioremediation of toxic dye accumulation.