Specific Spoilage Bacterium of Chilled Sturgeon Fillets and the Bacterial Reduction Effect of <scp> ClO ₂ </scp>

Chilled sturgeon fillets are highly perishable, posing a significant challenge to their long-distance transportation. This study aimed to identify the dominant spoilage bacteria in refrigerated sturgeon fillets and evaluate the effectiveness of chlorine dioxide (ClO₂) treatment in inhibiting bacterial growth and preserving product quality. The results indicated that spoilage microorganisms proliferated rapidly during storage, with sensory, physicochemical, and microbiological parameters reaching critical thresholds by the 10th day. High-throughput 16S rDNA sequencing revealed seven dominant spoilage bacteria: <i>Rahnella aquatilis</i>, <i>Pseudomonas fluorescens</i>, <i>Pseudomonas jessenii</i>, <i>Citrobacter freundii</i>, <i>Chryseobacterium indologenes</i>, <i>Hafnia alvei</i>, and <i>Serratia fonticola</i>. Among them, <i>Pseudomonas jessenii</i> was identified as the specific spoilage bacterium with significant spoilage activity. Using response surface methodology, the optimal ClO₂ treatment parameters for inhibiting <i>Pseudomonas jessenii</i> were determined to be a ClO₂ concentration of 36 μg/mL, a fillet thickness of 6 mm, and a soaking time of 17 min. The application of ClO₂ effectively reduced spoilage bacterial loads, offering a promising strategy for extending the shelf life of chilled sturgeon fillets.