Bioactive Peptide Production from Different Protein Sources Using Bioprospected Microbial Consortia

Bioactive peptides released from different protein sources have gained increasing attention in the diet due to their ability to modulate oxidative stress and other physiological functions. The type of bioactivity exerted depends on the peptide sequence and is therefore strongly associated with both the substrate sequence and the peptidase used for hydrolysis. In this context, the search for combinations of peptidases capable of producing hydrolysates with functional properties is highly relevant. The objective of this study was to obtain bioactive peptides through submerged bioprocesses using microbial consortia bioprospected from artisanal Canastra cheeses (Minas Gerais, Brazil). Bioprospecting and isolation were performed on Sabouraud medium, and microscopic analyses suggested the presence of yeasts and filamentous fungi, possibly belonging to genera such as Geotrichum, Yarrowia, Kluyveromyces, and Debaryomyces, which require confirmation by molecular identification. The microorganisms were inoculated into a medium containing 5 g/L malt extract, 1 g/L KH₂PO₄, 0.5 g/L MgSO₄·7H₂O, and 1 g/L (NH₄)₂SO₄ (control), supplemented with either 1% (w/v) casein or 1% (w/v) soybean meal, an agro-industrial residue, and incubated at 30 °C and 120 rpm for up to 72 h. The extracts were evaluated for pH, proteolytic activity, and DPPH radical-scavenging activity. Regarding proteolytic activity, casein was the most effective inducer compared with the control, resulting in an earlier production peak, whereas soybean meal did not significantly improve proteolytic activity. This difference may be related to the higher solubility and greater accessibility of casein proteins, whereas the more complex matrix of soybean meal may limit the availability of proteins and peptides for microbial utilization, enzyme induction and, consequentely, peptide release. For DPPH radical-scavenging capacity, casein showed the highest activity during the bioprocess, reaching approximately 15% at 48 h, whereas soybean meal reached a peak of 11% at 24 h. Although soybean meal showed lower antioxidant activity, its derived peptides may represent an interesting source of bioactive compounds, as they remain less explored than casein-derived peptides, while their production may also contribute to the valorization of this agro-industrial residue. Furthermore, antioxidant capacity did not correlate directly with peptidase activity, suggesting that the observed antioxidant potential may depend on the peptide profile rather than being determined only by the extent of proteolysis. These findings highlight the potential of bioprospected microbial consortia as sources of peptidases for the generation of peptide-rich extracts with bioactive potential, including from agro-industrial residues such as soybean meal, providing a basis for further investigation of their biological relevance in the context of nutrition and health.

The authors gratefully acknowledge PRPI/USP for its financial support. Ansanello, A.B.S., Silva, M.T., and Silva, B.F.K. acknowledge CNPq and CAPES for the scholarships received.