Qi Fengxia, Kreth Jens
University of Oklahoma Health Sciences Center BRC364, 975 NE 10th Street, Oklahoma City, OK, 73104, USA.
Oregon Health and Science University, Portland, OR, USA.
Methods Mol Biol. 2017;1537:203-218. doi: 10.1007/978-1-4939-6685-1_12.
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 microbiota. 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 developing novel approaches to manage these "polymicrobial diseases." In this chapter, we focus on a well-characterized form of biochemical warfare: bacteriocins produced by Streptococcus mutans, a primary dental caries pathogen, and hydrogen peroxide (HO) produced by several oral commensal streptococci. We will describe detailed methodologies on the competition assay, isolation, purification, and characterization of bacteriocins.
自然界中的大多数细菌以称为生物膜的多物种群落形式存在。在资源（营养、空间等）通常有限的自然栖息地中，单个物种必须与其他邻近物种竞争或合作，以便在多物种群落中延续下去。人类口腔中定植着700多种微生物，称为固有微生物群。这种固有菌群通常通过拮抗以及互利的种间相互作用维持生态平衡。然而，环境扰动可能会破坏这种平衡，导致致病物种过度生长，进而引发诸如龋齿（蛀牙）和牙周炎（牙龈疾病）等疾病。了解多样性维持机制可能有助于开发新方法来管理这些“多微生物疾病”。在本章中，我们重点关注一种特征明确的生化战形式：变形链球菌（一种主要的龋齿病原体）产生的细菌素，以及几种口腔共生链球菌产生的过氧化氢（H₂O₂）。我们将描述关于细菌素竞争测定、分离、纯化和表征的详细方法。
