Přejít k obsahu
Merck

Oxygen dependent pyruvate oxidase expression and production in Streptococcus sanguinis.

International journal of oral science (2011-04-13)
Lan-yan Zheng, Andreas Itzek, Zhi-yun Chen, Jens Kreth
ANOTACE

The objective of this study was to characterize the oxygen dependent regulation of pyruvate oxidase (SpxB) gene expression and protein production in Streptococcus sanguinis (S. sanguinis). SpxB is responsible for the generation of growth-inhibiting amounts of hydrogen peroxide (H2O2) able to antagonize cariogenic Streptococcus mutans (S. mutans). Furthermore, the ecological consequence of H2O2 production was investigated in its self-inhibiting ability towards the producing strain. Expression of spxB was determined with quantitative Real-Time RT-PCR and a fluorescent expression reporter strain. Protein abundance was investigated with FLAG epitope engineered in frame on the C-terminal end of SpxB. Self inhibition was tested with an antagonism plate assay. The expression and protein abundance decreased in cells grown under anaerobic conditions. S. sanguinis was resistant against its own produced H2O2, while cariogenic S. mutans was inhibited in its growth. The results suggest that S. sanguinis produces H2O2 as antimicrobial substance to inhibit susceptible niche competing species like S. mutans during initial biofilm formation, when oxygen availability allows for spxB expression and Spx production.

MATERIÁLY
Číslo produktu
Značka
Popis produktu

Sigma-Aldrich
Pyruvate Oxidase from microorganisms, lyophilized powder, ≥1.5 U/mg
Sigma-Aldrich
Pyruvate Oxidase from Aerococcus sp., lyophilized powder, ≥35 units/mg protein (biuret)