Study on bioactive molecules involved in extracellular biosynthesis of silver nanoparticles by <i>Penicillium aculeatum</i> Su1

Abstract

In this paper, the biosynthesis of high-stable and biocompatible silver nanoparticles (AgNPs) was implemented by employing cell-free filtrate of Penicillium aculeatum Su1. The compositions analysis of reducing biomolecules in reaction system before and after AgNPs synthesis suggested that proteins were mainly involved in the biosynthesis process of AgNPs. Polyacrylamide gel electrophoresis (SDS-PAGE) analysis displayed that two main protein bands with molecular weights ranging from 66.2 to 116 KDa and 35 to 45 KDa were capped on the surface of AgNPs. The further identification of these protein bands by liquid chromatography-mass spectrometry (LC-MS/MS) analysis indicated that actin as a major protein component was responsible for stabilization of prepared AgNPs. The activity of nitrate reductase secreted by P. aculeatum Su1 was 73.73 ± 3.89 μ g/(g · h). Furthermore, the dialysis assay showed that small molecular components had significant impacts on yield and particle size of biosynthesized AgNPs. Reduced nicotinamide adenine dinucleotide or reduced nicotinamide adenine dinucleotide phosphate (NADH or NADPH)-dependent nitrate reductases and other types of reductases or non-enzymatic bioactive molecules (≥ 3.5 KDa) might simultaneously participate in the biosynthesis process of AgNPs mediated by P. aculeatum Su1.