Biogenesis of bacterial cellulose/xanthan/CeO₂NPs composite films for active food packaging

The increasing significance of biopolymer-based food packaging can be attributed to its biodegradability and independence from petroleum-derived materials. Concurrently, metal oxide nanoparticles (NPs) have gained prominence as effective antimicrobial agents against both wild-type and antibiotic-resistant microbes. In this study, cerium oxide or ceria, CeO₂, nanoparticles with an average diameter of 50 nm were synthesized via a green method utilizing Vibrio sp. VLC cell lysate supernatant. The synthesized CeO₂ NPs displayed remarkable antimicrobial properties, inhibiting the growth of Escherichia coli and Staphylococcus aureus by 93.7 % and 98 %, respectively. To enhance the potential of bacterial cellulose (BC) for advanced applications, we developed a BC/xanthan/CeO₂ nanocomposite using both ex situ and in situ techniques. The integration of CeO₂ NPs within the nanocomposite structure not only improved the inherent properties of BC, but also rendered it suitable for use in active food packaging systems. The nanocomposite exhibited no significant cytotoxicity on the human dermal fibroblast (HDF) cells, confirming its safety. Nanocomposites containing biogenically synthesized CeO₂ NPs demonstrated exceptional efficacy for reducing microbial contamination. Bread samples coated with nanocomposite films displayed no signs of microbial growth. These results support the application of BC/xanthan/CeO₂ nanocomposites as suitable and effective coating materials for antimicrobial food packaging applications.