Enhancing Amino Acid and Fatty Acid Profiles Using Probiotic Fermentation of Catfish (Pangasius sp.) Waste for Sustainable Aquaculture

Abstract

The rapid expansion of catfish (Pangasius sp.) production in Indonesia has substantially increased organic waste generated from fillet processing, representing more than 45% of total fish biomass. Owing to its high protein and lipid contents, this waste has considerable potential for valorisation through probiotic-assisted solid-state fermentation. This study evaluated the growth of Lactobacillus plantarum ATCC 8014, Lactobacillus curvatus, and Bacillus subtilis, applied individually and as a consortium, and investigated their effects on proteolytic and lipolytic activities as well as essential amino and fatty acid production. All probiotic treatments reached optimal growth after 72 h of fermentation. L. curvatus exhibited the highest proteolytic activity (19.60 U mL-1) and produced the greatest total essential amino acid content (12,284.19 mg kg-1). B. subtilis showed lower proteolytic activity but selectively enhanced L-lysine and L-leucine concentrations. In contrast, L. plantarum ATCC 8014 demonstrated the highest lipolytic activity (1.36 U mL-1) and increased the levels of oleic acid, omega-6, and omega-3 fatty acids compared with non-fermented waste and other treatments. Overall, probiotic-assisted fermentation markedly improved proteolytic activity and essential amino acid production, whereas enhancements in lipolytic activity and fatty acid composition were comparatively limited. These findings demonstrate that probiotic solid-state fermentation is a promising strategy for upgrading the nutritional quality of catfish-processing waste while supporting sustainable waste valorisation in aquaculture.