Inactivating effects of the lactoperoxidase system on bacterial lyases involved in oral malodor production.

Inactivating effects of the lactoperoxidase system on bacterial lyases involved in oral malodor production. J Med Microbiol. 2015 Aug 3; Authors: Nakano M, Shin K, Wakabayashi H, Yamauchi K, Abe F, Hironaka S Abstract The main components of oral malodor have been identified as volatile sulfur compounds (VSCs) including hydrogen sulfide and methyl mercaptan. The lactoperoxidase (LPO) system (consisting of LPO, glucose oxidase, glucose, and thiocyanate) has been reported to exhibit antimicrobial activities against oral bacteria in vitro and suppressive effects on VSCs in mouth air in a clinical trial. We herein examined the in vitro effects of the LPO system on the activities of the bacterial lyases involved in the production of VSCs by oral anaerobes. The exposure of crude bacterial extracts of Fusobacterium nucleatum and Porphyromonas gingivalis or purified methionine γ-lyase to the LPO system resulted in the inactivation of their lyase activities through L-cysteine and L-methionine, which was linked to the production of hydrogen sulfide and methyl mercaptan, respectively. Exposing living F. nucleatum and P. gingivalis cells to the LPO system resulted in the suppression of cell numbers and lyase activities. The inactivation of the crude bacterial extracts of F. nucleatum and purified methionine γ-lyase by the LPO system was partly recovered by the addition of dithiothreitol. Therefore, the LPO system may inactivate bacterial lyases...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research