Аннотация
This study presents a comparative investigation of the structural and physicochemical properties of plant-derived cellulose extracted from agricultural residues (wheat, maize, cotton, and rice straw) and bacterial cellulose synthesized via fermentation using Komagataeibacter xylinus (K. xylinus). Plant-derived cellulose was obtained through an AlCl₃-glycerol pretreatment followed by alkaline purification, while bacterial cellulose was produced under static cultivation in a Hestrin – Schramm medium. The morphology, chemical structure, and thermal behavior of the resulting celluloses were systematically characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA/DTG). SEM analysis revealed that plant-derived cellulose exhibits elongated microfibrillar structures with fiber diameters ranging from 5 to 25 μm, accompanied by surface microcracks and pores resulting from effective removal of lignin and hemicellulose. In contrast, bacterial cellulose formed a dense, multilayered, and highly interconnected fibrillar network with significantly smaller fiber diameters (2.7-9.7 μm), reflecting its high structural uniformity and purity. FTIR spectra confirmed that both cellulose types share the same fundamental chemical backbone, while the weakening or absence of lignin-related absorption bands indicated efficient delignification and superior chemical purity in bacterial cellulose. Overall, the results demonstrate that plantderived and bacterial cellulose possess distinct yet complementary structural characteristics. Plant-derived cellulose provides a fibrous structural framework, whereas bacterial cellulose offers a nanostructured network, suggesting their potential combined use in sustainable biopolymer composites and environmentally friendly packaging materials.