Biotechnological Utilization of Amazonian Fruit: Development of Active Nanocomposites from Bacterial Cellulose and Silver Nanoparticles Based on Astrocaryum aculeatum (Tucumã) Extract

<b>Background/Objectives:</b> The rise of bacterial resistance and the search for alternative, biocompatible antimicrobial materials have driven interest in natural-based nanocomposites. In this context, silver nanoparticles (AgNPs) have shown broad-spectrum antibacterial activity, and bacterial cellulose (BC) is widely recognized for its high purity, hydrophilicity, and biocompatibility. This study aimed to develop a bio-based BC-AgNP nanocomposite via green synthesis using <i>Astrocaryum aculeatum</i> (tucumã) extract and assess its antimicrobial performance for wound dressing applications. <b>Methods:</b> BC was biosynthesized via green tea fermentation (20 g/L tea and 100 g/L sugar) and purified prior to use. AgNPs were obtained by reacting aqueous tucumã extract with silver nitrate (0.1 mmol/L) at pH (9) and temperature (40 °C). BC membranes were immersed in the AgNPs dispersion for 7 days to form the nanocomposite. Characterization was performed using UV-Vis, DLS, TEM, SEM-EDS, FTIR, XRD, ICP-OES, and swelling analysis. Antibacterial activity was evaluated using the disk diffusion method against <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> (ATCC 6538 and 4388). <b>Results:</b> The UV-Vis spectra revealed a gradual decrease in the surface plasmon resonance (SPR) band over 7 days of incubation with BC, indicating progressive incorporation of AgNPs into the membrane. ICP analysis confirmed silver incorporation in the BC membrane at 0.00215 mg/mL, corresponding to 15.5% of the initial silver content. Antimicrobial assays showed inhibition zones of 6.5 ± 0.5 mm for <i>S. aureus</i> and 4.3 ± 0.3 mm for <i>E. coli</i>. <b>Conclusions:</b> These findings validate the successful formation and antimicrobial performance of the BC-AgNP nanocomposite, supporting its potential use in wound care applications.