Myco-synthesis and characterization of silver nanoparticles using fungal laccase nanoparticles

Green synthesis of silver nanoparticles using microbial enzymes has gained considerable attention as an eco-friendly, cost-effective, biocompatible, and relatively simple alternative to conventional physical and chemical synthesis methods. The present study aimed to biosynthesize silver nanoparticles (Myco-AgNPs) using laccase nanoparticles derived from Ganoderma lucidum and to evaluate their antibacterial potential against selected pathogenic bacterial strains. The synthesized Myco-AgNPs were characterized using appropriate spectroscopic and microscopic techniques, which confirmed the successful formation of stable, predominantly spherical nanoparticles with favourable physicochemical properties. The antibacterial activity of the synthesized nanoparticles was evaluated using minimum inhibitory concentration (MIC) and well diffusion assays against both Gram-positive and Gram-negative bacteria. The tested bacterial strains exhibited varying degrees of susceptibility to the AgNPs, with MIC values ranging from 38 to 120 μg/mL. In the well diffusion assay, the highest tested concentration (30 µL) produced the maximum zones of inhibition against Staphylococcus aureus and Staphylococcus xylosus , followed by Escherichia coli and Pseudomonas aeruginosa . The greater susceptibility observed among certain bacterial strains may be associated with differences in cell-wall structure and the interaction of silver nanoparticles with cellular components. Overall, the findings demonstrate that laccase-mediated biosynthesis can provide an efficient and environmentally friendly approach for producing silver nanoparticles with notable antibacterial activity. The synthesized Myco-AgNPs therefore show promising potential for future antimicrobial applications, particularly where sustainable and biologically compatible nanomaterials are desirable. Further studies focusing on their mechanism of antibacterial action, cytotoxicity, stability, and application in real-world antimicrobial systems could help establish their practical utility.