Enhanced bacterial cellulose production from black soy sauce residue by Komagataeibacter xylinus: a sustainable bioconversion approach

This study explores the potential of black soy sauce residue (SSR), an agro-industrial by-product, as a carbon source for bacterial cellulose (BC) production by Komagataeibacter xylinus. The research systematically evaluated the efficacy of SSR-water mixtures at various ratios for BC cultivation, fermented under static conditions at room temperature over 7 days. The BC produced was thoroughly analyzed for its structural and physical properties using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The findings revealed that an SSR-water ratio of 1:50 yielded the highest BC production at 1.56 g/L, exceeding the synthetic Hestrin-Schramm (HS) medium yield. Moreover, the BC fibers derived from SSR exhibited a reduced diameter (34–39 nm) and enhanced crystallinity (89.3–93.7%) compared to those produced in HS medium. These results show the viability of SSR as a cost-effective and sustainable alternative to conventional BC production media.