1. What is Lactoperoxidase?
Lactoperoxidase is an enzyme, which is naturally present in fresh raw milk. Bovine milk contains about 30mg/l of Lactoperoxidase and the concentration is fairly constant throughout the lactation. Lactoperoxidase has no antibacterial effect on its own but has the ability to oxidise the thiocyanate ion (SCN–) in the presence of hydrogen peroxide (H2O2) (these components also exist naturally in tears, saliva, and gastric juices). The resulting chemical compound has an antibacterial effect in fresh raw milk. Against some species of normal gut flora such as streptococci and lactobacilli, the resulting compound has a bacteriostatic effect (inhibiting bacterial growth) while it has bactericidal effect (killing bacteria) against some gram-negative bacteria, i.e. Escherichia coli, pseudomonads.
Lactoperoxidase SCN – + H2O2 ———————— OSCN – + H2O (Thiocyanate ion) + (Hydrogen Peroxide)——
(Antibacterial compound)