Optimization fermentation of black soldier fly larvae pulp for enhanced growth performance and nutritional properties in yellow catfish

The aquaculture industry must identify sustainable protein sources, driven by projections of a 70% increase in demand for aquatic food by 2050. Black soldier fly larvae (BSFL) present a viable and promising alternative, converting organic waste into biomass rich in crude protein. However, their industrial application is compromised by issues of perishability and nutrient degradation. This study proposes a refined fermentation process, utilizing Bacillus velezensis GL-2 and Lactiplantibacillus plantarum GL-4, to augment the nutritional profile and enhance the shelf life of BSFL. The optimal fermentation conditions (35°C, pH 6.4, 6.92 days) significantly increased acid-soluble protein content to 25.63% and reduced pH to 4.22. The fermented BSFL pulp (FBSFP) also demonstrated robust antibacterial activity against prominent aquatic pathogens, including Aeromonas hydrophila and Vibrio . In vivo trials involving yellow catfish revealed that dietary inclusion of 5%–10% FBSFP markedly improved growth performance and nutrient utilization. The specific growth rates for the 5% and 10% FBSFP groups were about (1.9% day⁻¹ and 2.0% day⁻¹, respectively) notably surpassing the control group. Moreover, FBSFP supplementation resulted in enhanced lysozyme activity and crude protein retention in the fish. These outcomes underscore the potential of FBSFP to serve as a sustainable, high-value substitute for conventional protein sources in aquaculture feeds. • Optimized fermentation conditions elevate ASP in FBSFP to 25.63%. • FBSFP exhibits antibacterial activity against key aquatic pathogens. • Yellow catfish fed containing 5%–10% FBSFP show improved growth and nutrient utilization. • Fermentation process enhance lysozyme activity and crude protein content in yellow catfish. • This study establishes FBSFP as a sustainable aquafeed applications.