Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans

Abstract

An enzyme found to be crucial to the growth and survival of a bacterium found in the mouth could be targeted to prevent tooth decay. The Streptococcus mutans bacterium is a major cause of tooth decay; fed by high sugar intake, it generates acid that leads to tooth demineralization. Ming-Yun Li and co-workers at Sichuan University in Chengdu, China, have demonstrated that an enzyme called alanine racemase (Alr) is crucial to the growth and maintanance of S. mutans cell wall structure. The team created alr mutant strain of the bacterium, and discovered that without the enzyme the bacterium cell wall tore easily, leading to cell disintegration. They also found that deleting Alr significantly reduced the bacterium's ability to compete effectively with other oral bacteria. The manipulation of the enzyme in oral biofilm could help reduce tooth decay.

Keywords

alanine racemase / biofilm / D-alanine / dental caries / Streptococcus mutans

References

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