Oral Biology pp 151-166 | Cite as

Characterization of Anti-competitor Activities Produced by Oral Bacteria

  • Fengxia Qi
  • Jens Kreth
Part of the Methods in Molecular Biology book series (MIMB, volume 666)


Most bacteria in nature exist in multispecies communities known as biofilms. In the natural habitat where resources (nutrient, space, etc.) are usually limited, individual species must compete or collaborate with other neighboring species in order to perpetuate in the multispecies community. The human oral cavity is colonized by >700 microbial species known as the indigenous microflora. This indigenous flora normally maintains an ecological balance through antagonistic as well as mutualistic interspecies interactions. However, environmental perturbation may disrupt this balance, leading to overgrowth of pathogenic species, which could in turn initiate diseases such as dental caries (tooth decay) and periodontitis (gum disease). Understanding the mechanisms of diversity maintenance may help development of novel approaches to manage these “polymicrobial diseases.” In this chapter, we will focus on a well-characterized form of biochemical warfare: bacteriocins produced by Streptococcus mutans, a primary dental caries pathogen, and H2O2 produced by Streptococcus sanguinis, an oral commensal. We will describe detailed methodologies on the competition assay, isolation, purification, and characterization of bacteriocins.

Key words

Bacteriocins oral streptococci interspecies competition biofilms luciferase reporter 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Fengxia Qi
    • 1
  • Jens Kreth
    • 2
  1. 1.College of Dentistry, University of Oklahoma Health Sciences CenterOklahoma CityUSA
  2. 2.Department of Microbiology and ImmunologyUniversity of Oklahoma Health Sciences CenterOklahoma CityUSA

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