Acid Production by Oral Strains of Candida albicans and Lactobacilli
Acid Production by Oral Strains of Candida albicans and Lactobacilli
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DOI：
10.1159/000204911
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发表时间：
2009-01-01
期刊：
影响因子：
4.2
通讯作者：
Klimm, W.
中科院分区：
文献类型：
--
作者：
Klinke, T.;Kneist, S.;Klimm, W.
白色念珠菌和乳酸菌都是儿童和青少年龋齿病变的常见定植菌。本研究的目的是比较不同pH值和葡萄糖浓度下白色念珠菌和几种乳杆菌的产酸速度。通过培养共28个口腔分离株，包括白色念珠菌、鼠李糖乳杆菌、副干酪乳杆菌、副干酪乳杆菌耐受性和德布鲁克氏乳杆菌，获得洗涤后的纯静息细胞悬液。在自动pH-stat系统中用NaOH反复滴定，在恒定pH 7.0、5.5、5.0和4.0条件下测定葡萄糖的产酸量。在中性和低pH条件下，酵母和乳酸菌的产酸率相似，而在中等酸性环境下，白色念珠菌的产酸率低于乳酸菌。滴定后的无细胞培养基的离子色谱分析显示，丙酮酸是白色念珠菌分泌的主要有机酸阴离子。在中性条件下，有机酸占酵母总酸产量的比例低于10%，而在pH 4.0时为42-66%。与乳酸菌相比，酵母需要大约50倍的葡萄糖浓度才能以最大速度的一半产生酸。考虑到文献中关于早期儿童龋齿病变中微生物的频率和比例的临床数据，口腔乳酸菌和白色念珠菌对总体微生物酸形成的贡献似乎很重要。版权所有(C) 2009 S. Karger AG，巴塞尔
Both Candida albicans and lactobacilli are common colonizers of carious lesions in children and adolescents. The purpose of this study is to compare the velocity of acid production between C. albicans and several Lactobacillus species at different pH levels and concentrations of glucose. Washed, pure resting-cell suspensions were obtained by culturing a total of 28 oral isolates comprising the species C. albicans, Lactobacillus rhamnosus, Lactobacillus paracasei paracasei, Lactobacillus paracasei tolerans and Lactobacillus delbrueckii lactis. Acid production from glucose was determined at a constant pH of 7.0, 5.5, 5.0 and 4.0 by repeated titrations with NaOH in an automated pH-stat system. Acid formation rates of yeast and lactobacilli proved to be similar at both neutral and low pH, while in a moderately acidic environment C. albicans produced less acid than the lactobacilli. Ion chromatographic analysis of the cell-free medium after titration revealed pyruvate to be the predominant organic acid anion secreted by C. albicans. The proportion of organic acids to overall acid production by the yeast was below 10% at neutral conditions, in contrast to 42-66% at pH 4.0. Compared to lactobacilli, yeast required a concentration of glucose that was about 50 times higher to allow acid production at half the maximum speed. Considering the clinical data in the literature about the frequency and proportions of microorganisms present in early childhood caries lesions, the contribution of oral lactobacilli as well as C. albicans to overall microbial acid formation appears to be important. Copyright (C) 2009 S. Karger AG, Basel