Preparation and evaluation of antibacterial activity of Ag+ supported modified Japanese cedar biomass
摘要
A novel antibacterial agent was synthesized from Japanese cedar sawdust, a representative woody biomass resource, through chemical modification using potassium permanganate. The oxidation treatment introduced carboxyl groups onto the biomass surface, providing active sites for Ag+ adsorption. X-ray photoelectron spectroscopy (XPS) analysis revealed characteristic Ag 3d peaks at 367.8 and 373.8 eV, confirming the successful adsorption of Ag+ onto the modified biomass. The saturated adsorption capacities of Ag+ were determined to be 48.3 mg g− 1 by the batch method and 73.5 mg g− 1 by the column method. The antibacterial activity of the resulting Ag+-adsorbed material (Cedar-O-Ag) was evaluated against Escherichia coli by observing turbidity, Ag+ release, and colony formation. Cedar-O-Ag induced bacterial cell lysis, with complete bactericidal activity observed at 50 mg, corresponding to an Ag+ concentration of 0.347 mmol L− 1. Colony formation assays confirmed that E. coli growth was entirely inhibited at this concentration. Furthermore, reusability tests demonstrated that Cedar-O-Ag maintained bactericidal activity for up to three consecutive cycles. Overall, these results show that woody biomass can serve as an effective, sustainable, and reusable carrier for antibacterial materials.