Chemical induced fabrication of silver nanoparticles (Ag-NPs) as nanocatalyst with alpha amylase enzyme for enhanced breakdown of starch

• Published in: Biocatalysis and agricultural biotechnology 2018-07, Vol.15, p.377-383
• Main Authors: Krishnakumar, S., Janani, P., Mugilarasi, S., Kumari, Ganita, Janney, J. Bethanney
• Format: Article
• Language: English
• Subjects: FTIR; Nanocatalyst; Silver nanoparticles; Starch hydrolysis; UV–vis spectroscopy; Zeta potential
• ISSN: 1878-8181; 1878-8181
• DOI: 10.1016/j.bcab.2018.06.016

Silver nanoparticles (Ag-NPs) have been used as promising catalytic materials for various applications. The objective of the present study is the fabrication of silver nanoparticles by chemical method for nanocatalytic degradation of starch using alpha amylase enzyme. The present study demonstrates sodium borohydride is used for the fabrication of silver nanoparticles. The fabrication of the silver nanoparticles was monitored visually and using UV–visible absorption spectroscopy. Silver nanoparticles were characterized by UV–visible spectroscopy, FTIR, Zeta sizer, Zeta potential and antimicrobial efficacy. Silver nanoparticle with amylase enzyme is utilized for enhanced degradation of starch in a catalyzed reaction of starch hydrolysis by DNS assay method. UV–Vis spectroscopy revealed the fabrication of silver nanopartícles exhibiting the typical surface plasmon absorption at 430 nm. The three major functional moieties are proteins, aromatic groups and hydroxyl groups. These are responsible for the instant reduction of silver salts into silver ions recorded in FTIR spectra. The zeta potential of nanoparticle was found to be sharp peaked at − 31.7 mV. Antimicrobial activity of nanoprticles revealed more susceptible against Gram positive bacteria than Gram negative bacteria and Candida albicans. An increased formation of reducing sugar around 40 fold confirmed the catalytic activity of purified bacterial amylase enzyme mixed with Ag-NPs as nanocatalyst. The present study suggests that immobilization of amylase enzyme onto the surface of Ag-NPs as nanocatalyst can be a useful approach for increased degradation of complex starch molecules into simple sugars, which can be utilized for diverse industrial applications.