Bowden G H, Li Y H
Department of Oral Biology, Faculty of Dentistry, University of Manitoba, Winnipeg, Canada.
Adv Dent Res. 1997 Apr;11(1):81-99. doi: 10.1177/08959374970110012101.
The amounts and types of nutrients in the environment influence the development and final bacterial and chemical composition of biofilms. In oligotrophic environments, organisms respond to nutrient stress by alterations in their cell morphology and cell surfaces, which enhance adherence. Little is known of the responses to stress by bacteria in the animal oral cavity. The environment in the oral cavity is less extreme, and saliva provides a constant source of nutrients. Catabolic cooperation among oral bacteria allow carbon and nitrogen from salivary glycoproteins to be utilized. Modification of growth environments of oral bacteria can influence their cell surfaces and adhesion. Studies in experimental animals have shown that feeding either glucose or sucrose diets or fasting has little effect on the initial stages of development of oral biofilms. However, diet can influence the proportions of different bacterial species later in biofilm development. Studies of competition among populations in communities of oral bacteria in vitro and in vivo have shown the significance of carbon limitation and excess and changes in environmental pH. Relatively few studies have been made of the role of a nitrogen metabolism in bacterial competition in biofilms. In keeping with biofilms in nature, oral biofilms provide a sequestered habitat, where organisms are protected from removal by saliva and where interactions among cells generate a biofilm environment, distinct from that of saliva. Oral biofilms are an essential component in the etiologies of caries and periodontal disease, and understanding the biology of oral biofilms has aided and will continue to aid in the prevention and treatment of these diseases.
环境中营养物质的数量和种类会影响生物膜的发育以及最终的细菌和化学组成。在贫营养环境中，生物体通过改变细胞形态和细胞表面来应对营养胁迫，这会增强黏附性。对于动物口腔中细菌对应激的反应了解甚少。口腔环境没那么极端，唾液提供了持续的营养来源。口腔细菌之间的分解代谢协作使得唾液糖蛋白中的碳和氮得以利用。改变口腔细菌的生长环境会影响它们的细胞表面和黏附性。对实验动物的研究表明，喂食葡萄糖或蔗糖饮食或禁食对口腔生物膜发育的初始阶段影响不大。然而，饮食会在生物膜发育后期影响不同细菌种类的比例。对口腔细菌群落中种群间竞争的体外和体内研究表明了碳限制、碳过量以及环境pH值变化的重要性。关于氮代谢在生物膜细菌竞争中的作用的研究相对较少。与自然环境中的生物膜一样，口腔生物膜提供了一个隔离的栖息地，在那里生物体受到保护，不会被唾液冲走，而且细胞间的相互作用产生了一个与唾液不同的生物膜环境。口腔生物膜是龋齿和牙周病病因中的重要组成部分，了解口腔生物膜的生物学特性已经并将继续有助于预防和治疗这些疾病。
