Fermentation of Lily Waste With an Autochthonous Bacillus velezensis Strain: Structural Modification and Functional...

The processing of edible lily generates substantial waste, including root remnants, fibrous roots, and bulb fragments, the improper disposal of which poses significant environmental risks. Consequently, the effective valorization of these by-products represents a critical challenge. In this study, a high cellulase-producing strain of Bacillus velezensis was isolated from lily bulbs, and its enzymatic capacity was harnessed to convert insoluble dietary fiber (IDF) present in lily waste into soluble dietary fiber (SDF), which is more readily absorbed by the human body. The results revealed that the SDF content increased from 6.49% to 13.92%, accompanied by elevated levels of functional monosaccharides, including fucose, galactose, and mannose. SEM and FT-IR analyses demonstrated that the fermentation process disrupted the dense microstructure of the dietary fiber and gave rise to a honeycomb-like morphology. Thermogravimetric analysis (TGA) and x-ray diffraction (XRD) data further indicated that the crystallinity of the treated dietary fiber increased from 13.08% to 20.18%. Moreover, the functional properties-specifically the hypoglycemic and hypolipidemic effects-as well as the antioxidant activity of the fermented fiber were superior to those of the untreated counterpart. These findings demonstrated that treatment of lily waste with B. velezensis effectively modified the structural and functional attributes of dietary fiber, thereby enhancing the utilization value of lily processing by-products.