Valorization of tilapia processing waste for sustainable production of fungal lipopeptide biosurfactant

Abstract

The aquaculture industry generates a significant amount of organic waste, particularly from tilapia (Oreochromis niloticus) processing. Among these residues, tilapia viscera stand out for their high protein and lipid content, representing a promising but still underexplored resource for biotechnological applications. In this context, this study investigated the use of tilapia viscera broth (TVB) as a low-cost, renewable substrate for biosurfactant production by Penicillium rubens UCP 1213, aiming to contribute to the fish waste valorization. A 2² full-factorial design was applied to evaluate the effects of TVB and post-frying soybean oil (PFSO) as a component of the culture medium for biosurfactant production. The best results were achieved with 9% TVB and 3% PFSO, reducing surface and interfacial tensions to 35.68 and 6.4 mN/m, respectively. The biosurfactant was recovered by acid precipitation (1.36 g/L); its anionic profile was confirmed by zeta potential measurement, while preliminary compositional and spectroscopic analyses indicated a predominantly lipopeptide nature. Phytotoxicity assays showed no evidence of toxic effects on onion seed germination, indicating preliminary environmental safety. Overall, this study demonstrates the feasibility of using tilapia viscera as a renewable substrate for the sustainable production of fungal biosurfactant, reinforcing circular economy practices and contributing to waste mitigation in aquaculture. The results highlight the potential of this waste-derived lipopeptide and support further process optimization and broader toxicological evaluation for industrial and agricultural applications.