Analysis of Structural Characteristics of Bacterial Nanocellulose Synthesized Using Beechwood Hydrolysate

In this study, a comprehensive structural analysis to increase yield, optimize cultivation parameters, and evaluate bacterial nanocellulose (BNC) organization using two types of media was conducted. Cultivation of Komagataeibacter xylinus (K. xylinus) DSM 46591 was performed in an alternative beechwood hydrolysate medium (BH) and the standard Hestrin–Schramm medium (HS) over a period of 72–432 h. High–performance liquid chromatography (HPLC) confirmed the successful extraction of glucose, xylose, and associated compounds from the wood. Fourier–transform infrared spectroscopy (FTIR) revealed visible changes in supramolecular structure in BH, resulting in a 12.8% decrease in the lateral order index (LOI: 0.748 → 0.652) and a simultaneous increase in the hydrogen bond index (HBI: 0.997 → 1.111) in comparison with HS. X–ray diffraction (XRD) showed that BH promotes the synthesis of a combination of cellulose triclinic (Iα) and monoclinic (Iβ) with a high crystallinity index (CI = 86%), while sterically limiting lateral crystallite growth (the crystallite sizes (CS) of the (002) crystallographic plane were 6.1–6.5 nm for BH vs. 6.7 nm for HS). Scanning electron microscopy (SEM) confirmed that, in BH, this resulted in a reticulated, interconnected three–dimensional nanofibrillar matrix with preserved capillary porosity. In contrast, the HS samples showed pore clogging, denser fibre packing, and layer stacking.