Characterization of sustainable bacterial cellulose of Komagataeibacter rhaeticus SLAM-JS1B isolated from Kombucha for biocontrol of Salmonella Typhimurium in animal production system

Bacterial cellulose (BC) is a high-purity, nanofibrillar biomaterial with considerable potential in the animal industry as both a functional dietary fiber and a carrier for bioactive compounds. In this study, three BC-producing <italic>Komagataeibacter</italic> strains were isolated from kombucha pellicles (<italic>K. intermedius</italic> SLAM-NK6B, <italic>K. rhaeticus</italic> SLAM-JS1B, and <italic>K. rhaeticus</italic> SLAM-JS2B), and their cellulose production under static conditions at 25°C was compared. The <italic>K. rhaeticus</italic> strains formed substantially thicker pellicles than <italic>K. intermedius</italic> with dry weight yields of 120.8 ± 28.3 mg/L (SLAM-JS1B), 113.3 ± 15.0 mg/L (SLAM-JS2B), and 36.3 ± 5.3 mg/L (SLAM-NK6B), respectively. Leveraging the highest-yielding strain SLAM-JS1B, a sequential optimization strategy including one-variable-at-a-time (OVAT) screening, Plackett–Burman design (PBD), and Box–Behnken design (BBD) combined with response surface methodology, was employed to enhance BC production. Yeast extract, MgSO₄, and ethanol were identified as key drivers. The optimized medium (10 g/L yeast extract, 2 g/L MgSO₄, 10 mL/L ethanol, with glucose and KH₂PO₄ maintained within the design-space ranges) yielded a cellulose titer of 2.795 g/L, representing a 37% increase relative to the baseline Saleh medium. Characterization by FT-IR and FE-SEM confirmed the structural, chemical, and morphological characteristics of BC, revealing a dense, highly porous nanofibrillar network. Furthermore, <italic>Salmonella</italic> Typhimurium–targeting phages were successfully immobilized on the BC matrix and retained lytic activity in antimicrobial assays. Collectively, our findings propose an optimized production platform for BC using <italic>K. rhaeticus</italic> SLAM-JS1B isolated from kombucha and highlight the functional utility of BC as a carrier for bioactives, underscoring its promise for pathogen biocontrol in animal production systems.