Purification and Characterization of Amylase From Priestia megaterium SFA and Green Synthesis of Nanoparticles

ABSTRACT This study focused on the isolation of amylase‐producing bacteria from decaying potato peels, the identification of the isolate with the highest amylase activity, the characterization of the enzyme, and nanoparticle (NP) biosynthesis using culture supernatant. Among 40 isolates, Priestia megaterium SFA (GenBank Accession No.: OR415891.1) exhibited the highest amylase activity (0.76 U/mL). The enzyme was subsequently purified through ammonium sulfate precipitation, ultrafiltration, and anion exchange chromatography, achieving a 20.4‐fold increase in purity, a 9.6% yield, and a specific activity of 10.2 U/mg. Biochemical characterization revealed a molecular weight of 57 kDa, a maximum reaction velocity ( V max ) of 13.3 U/mg protein, and a Michaelis constant ( K m ) of 4.5 mg/mL. The amylase exhibited optimal activity at pH 9.0 and 40°C and maintained stability in the presence of various metal ions, reagents, and organic solvents. Notably, the amylase‐containing culture supernatant enabled the successful biosynthesis of copper (Cu) and magnesium (Mg) NPs, highlighting its potential as a biocatalyst for green nanotechnology applications. The synthesized NPs were confirmed and characterized using UV–visible spectroscopy, Fourier‐transform infrared (FT‐IR) spectroscopy, x‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses.