Nutritional value improvement of soybean meal through solid-state fermentation by proteases-enhanced Streptomyces sp. SCUT-3

Abstract

With the global population expected to reach 10 billion by the 2050s, the demand for protein will surge, intensifying the need for high protein utilization efficiency. This study investigates the use of protease-enhanced Streptomyces sp. SCUT-3-3940 to degrade soybean meal (SBM) via solid-state fermentation (SSF). Optimized conditions resulted in anti-nutritional factors elimination and high soluble protein recovery (41.1 g/100 g), including bioactive oligopeptides (17.3 g/100 g) with antihypertensive and antioxidant properties. The degradation also produced free amino acids rich in essential amino acids, and other nutrient enhancing compounds. The fermented SBM (FSBM) exhibited superior digestibility, making it a valuable protein source. In a 60-day largemouth bass trial, replacing 10 % SBM with FSBM in feed significantly improved feed intake and weight gain. This method offers an efficient, eco-friendly, and cost-effective solution to address global protein shortages.

Keywords: Protein digestibility improvement; Solid-state fermentation; Soybean meal.