Random mixtures of antimicrobial peptides inhibit bacteria associated with pasteurized bovine milk.

The shelf life of pasteurized bovine milk is limited by microorganism activity as surviving bacteria continue to grow in the bovine milk, eventually causing milk spoilage. In the current study, we used matrix-assisted laser desorption ionization time of flight mass spectrometry to identify pasteurized bovine milk-associated mesophilic and psychrotrophic bacteria. We have recently designed random cationic peptide mixtures that possess strong antimicrobial and antibiofilm properties. These compounds are cheap and easy to synthesize and represent a new class of antimicrobial agents. Here, we show that the random peptide mixtures are able to efficiently eradicate the bacteria identified as associated with pasteurized bovine milk, and reduced significantly the growth of Bacillus subtilis in milk. We propose these antimicrobial peptides as potential candidates for integration in bioactive milk and food packaging to prevent bacterial growth and extend the shelf life of food.