摘要：This work describes an antibacterial enzyme system based on the aerobic conversion of extracellular L-lactic acid to pyruvic acid and hydrogen peroxide using the enzyme L-lactate oxidase (2-hydroxyacid oxidase). Subsequent production of hypothiocyanate ions by hydrogen peroxide in the presence of salivary thiocyanate and sialoperoxi-dase should lead to a rapid and selective inhibition of dental plaque bacteria. This system was tested in glucose cultures of oral bacteria and results showed inhibition of acid production in the presence of saliva suggesting that the enzyme shows potential for antibacterial activity under the conditions found in the mouth. The action of lactate oxidase was compatible with the enzymes found in Zendium (Oral-B) dentrifice and a mixture of the two gave cumulative inhibition. A hydrated aluminium oxide gel provided a substratum for concentrating the enzyme and binding it to salivary bacterial-protein aggregates.Keywords: 2-hydroxyacid oxidase, lactate oxidase, peroxidase, saliva, thiocyanate.
