Department of Earth Sciences, University of Minnesota, Minneapolis, Minnesota, USA.
Department of Microbiology, Immunology, and Cancer Biology, University of Minnesota, Minneapolis, Minnesota, USA.
Appl Environ Microbiol. 2018 Mar 19;84(7). doi: 10.1128/AEM.02440-17. Print 2018 Apr 1.
Bacteria that accumulate polyphosphates have previously been shown to dynamically influence the solubility of phosphatic minerals in marine settings and wastewater. Here, we show that dental plaque, saliva, and carious lesions all contain abundant polyphosphate-accumulating bacteria. Saturation state modeling results, informed by phosphate uptake experiments using the model organism , which is known to inhabit advanced carious lesions, suggest that polyphosphate accumulation can lead to undersaturated conditions with respect to hydroxyapatite under some oral cavity conditions. The cell densities of polyphosphate-accumulating bacteria we observed in some regions of oral biofilms are comparable to those that produce undersaturated conditions (i.e., those that thermodynamically favor mineral dissolution) in our phosphate uptake experiments with These results suggest that the localized generation of undersaturated conditions by polyphosphate-accumulating bacteria constitutes a new potential mechanism of tooth dissolution that may augment the effects of metabolic acid production. Dental caries is a serious public health issue that can have negative impacts on overall quality of life and oral health. The role of oral bacteria in the dissolution of dental enamel and dentin that can result in carious lesions has long been solely ascribed to metabolic acid production. Here, we show that certain oral bacteria may act as a dynamic shunt for phosphate in dental biofilms via the accumulation of a polymer known as polyphosphate-potentially mediating phosphate-dependent conditions such as caries (dental decay).
先前已有研究表明，积累多聚磷酸盐的细菌会在海洋环境和废水中动态影响磷酸质矿物的溶解度。在这里，我们表明牙菌斑、唾液和龋齿病变中都含有丰富的聚磷酸盐积累细菌。通过使用已知栖息在龋齿病变中的模式生物进行磷酸盐摄取实验，并结合饱和度状态建模结果表明，在一些口腔环境条件下，聚磷酸盐的积累可能导致羟磷灰石不饱和。我们在口腔生物膜的一些区域观察到的聚磷酸盐积累细菌的细胞密度与那些在磷酸盐摄取实验中产生不饱和条件（即热力学上有利于矿物溶解的条件）的细菌相当。这些结果表明，聚磷酸盐积累细菌产生的局部不饱和条件可能构成牙齿溶解的一种新的潜在机制，可能会增强代谢性产酸的影响。龋齿是一个严重的公共卫生问题，会对整体生活质量和口腔健康产生负面影响。口腔细菌在溶解牙釉质和牙本质导致龋齿病变方面的作用长期以来一直被单纯归因于代谢性产酸。在这里，我们表明某些口腔细菌可能通过积累一种称为多聚磷酸盐的聚合物，在牙齿生物膜中充当磷的动态分流器，从而潜在地介导与龋齿（牙齿腐烂）相关的磷酸盐依赖条件。
