Abstract

The present study was aimed at utilization of biosynthesized silver nanoparticles (AgNPs) and its mediated synthetic melanoidin decolourization using bacterial extract in an immobilized condition. Biosynthesis of silver nanoparticles was done by using the Bacillus sp. BAC1 via extracellular methodology. Brown color biosynthesized silver nanoparticles were characterized using UV-Visible spectroscopic analysis. Further characterization using Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR) and Atomic force microscopic (AFM) analysis revealed that nanoparticles were spherical in shape with smooth surface morphology. Bacterial extracellular supernatant exhibited more than 65% of melanoidin decolourization (in 12 h) under normal conditions. In contrast, under similar conditions, biosynthesized AgNPs showed 82% removal. The cell free extract immobilized with synthesized AgNPs yields maximum melanoidin removal 92% in 12 h; this emphasizes nano-coupled biomaterial immobilization as a suitable technique for rapid melanoidin decolourization.

Key words: Melanoidin, Molasses spent wash, Decolourization, Silver nanoparticle, Immobilization.