<p dir="ltr">The research provides a comprehensive characterization of the activities of several serine peptidases, including prolyl oligopeptidases (POP, S9A subfamily), oligopeptidase B (OpdB, S9B), acylaminoacyl peptidases (S9C), proline iminopeptidases (PIP, S33), and subtilisin family proteases (S8), produced by diverse species of oral bacteria, revealing differences in their biochemical properties. Although the exact biological roles of these peptidases in oral health and disease remain to be fully understood, the findings here greatly enhance our knowledge of the biochemical functions of serine peptidases in oral bacteria and lay a valuable foundation for further research.</p>