Which enzyme in saliva destroys bacteria by digesting their cell walls?

1. Barrier defenses are not a response to infection, they work continuously to protect against a broad range of pathogens. 2. The saliva in the mouth is rich in lysozyme, an enzyme that destroys bacteria by digesting their cell walls. 3. Perforin and granzyme sit in the granules of natural killer cells, and histamine is a mast cell mediator of inflammation, so none of the three belongs to saliva. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 21 "The Lymphatic and Immune System", section 21.2 Barrier Defenses and the Innate Immune Response_