Extraction of chondroitin sulfate from chicken cartilage by Bacillus velezensis 259 fermentation: whole-genome analysis and process optimization

This study used chicken cartilage as the raw material and employed microbial fermentation with Bacillus velezensis 259 (B. velezensis 259) to extract chondroitin sulfate (CS). The CS extraction rate served as the primary evaluation index to investigate the effects of bacterial inoculation amount, cartilage addition amount, and fermentation time on extraction efficiency. First, B. velezensis 259 was evaluated for its gelatinolytic and proteolytic activities and safety-related characteristics, followed by whole-genome analysis to investigate its genomic features and the presence of potential virulence and antimicrobial resistance genes. Subsequently, single-factor experiments and response surface optimization were conducted. A quadratic polynomial model was established using the Box-Behnken design, and response surface analysis was performed to determine the optimal process parameters for CS extraction from fermented chicken cartilage using B. velezensis 259. The results showed that the optimal extraction conditions were 6.2% inoculation amount, 22.5% cartilage addition amount, 37 °C, 180 r/min and 20.8 h fermentation time. Under these conditions, the CS extraction rate reached 17.9%. In addition, UV and Raman spectroscopy further showed that the crude CS extract exhibited spectral characteristics similar to those of the CS-A and CS-C standards. These findings demonstrated the feasibility of using B. velezensis 259 fermentation for CS extraction from chicken cartilage and provided optimized process parameters for this approach.

The online version contains supplementary material available at https://doi.org/10.1007/s13205-026-05101-6.