The Discovery of New Antilisterial Proteins FromPaenibacillus polymyxaKp10 via Genome Mining and Mass Spectrometry

The inhibitory properties of novel antimicrobial proteins against food-borne pathogens such asListeria monocytogenesoffer extensive benefits to the food and medical industries. In this study, we have identified antimicrobial proteins from a milk curd-derived bacterial isolate that exhibits antilisterial activity using genome mining and mass spectrometry analysis. The analysis of the draft genome sequence identified the isolate asPaenibacillus polymyxaKp10, and predicted the presence of antimicrobial paenibacillin, paenilan, paeninodin, sactipeptides, thiazole-oxazole modified microcin, and histone-like DNA binding protein HU encoded in its genome. Interestingly, nanoLC-MS/MS analysis identified two histone-like DNA binding proteins HU as predictedin silicoearlier, exhibiting antilisterial activity. Additionally, translation initiation factor IF-1 and 50S ribosomal protein L29 were also discovered by the mass spectrometry in the active fractions. The antilisterial activity of the four proteins was verified through heterologous protein expression and antimicrobial activity assayin vitro. This study has identified structural regulatory proteins fromPaenibacilluspossessing antilisterial activity with potential future application in the food and medical industries.