Circular bioprocessing of bovine blood for peptide-based antimicrobial and antibiofilm agents.

The growing accumulation of bovine blood from slaughterhouses represents a significant environmental challenge and an untapped bioresource. To address this, we evaluated three starter strains isolated from fermented coffee beans (Torulaspora delbrueckii, Lactiplantibacillus plantarum, and Bacillus coagulans) for their ability to generate bovine blood peptidic hydrolysates (BBPHs). The resulting peptidic hydrolysates exhibited potent antimicrobial and antibiofilm activities against multidrug-resistant pathogens, including Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. Notably, the T. delbrueckii-derived hydrolysate (BBPH1) demonstrated the strongest bioactivity profile. Purification and liquid chromatography-tandem high-resolution mass spectrometry (LC-HRMS) based peptide mapping of BBPH1 revealed five previously unreported antimicrobial peptides, whose bioactivities were validated against target pathogens. Our findings demonstrate that targeted microbial fermentation of bovine blood can yield functionally relevant peptide fractions, supporting the feasibility of integrating slaughterhouse by-product valorization into sustainable antimicrobial development pipelines and advancing circular-economy principles.