EFFECTS OF PULSING WITH XYLITOL ON MIXED CONTINUOUS CULTURES OF ORAL STREPTOCOCCI
EFFECTS OF PULSING WITH XYLITOL ON MIXED CONTINUOUS CULTURES OF ORAL STREPTOCOCCI
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DOI：
10.1111/j.1834-7819.1991.tb04709.x
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发表时间：
1991-06-01
影响因子：
2.1
通讯作者：
GULLY, NJ
中科院分区：
文献类型：
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作者：
ROGERS, AH;PILOWSKY, KA;GULLY, NJ
连续培养是一种使生物体能够以接近自然发生的速率生长的手段。 此外，向培养容器中添加瞬时过量的各种营养物（“脉冲”）的效果模拟了饮食挑战对牙菌斑生物体的效果。 变形链球菌T8和米勒链球菌B448的混合培养物在化学成分确定的培养基中，在5%二氧化碳的氮气气氛下，以D = 0.1 h-1的稀释率和控制的pH值为7.0的葡萄糖限制下生长。 调节培养基储库中精氨酸的水平，使得链球菌。milleri占优势的链球菌。变种人稳定共存 平衡后，将培养容器用各种碳水化合物脉冲至终浓度为5 × 10（-2）mol/L。 然后定期取样，并对链球菌活菌进行分类计数。变形链球菌和链球菌。milleri在mitissalivarius琼脂上进行。 结果表明，用葡萄糖、果糖、“偶联糖”、乳糖、木糖和山梨糖醇脉冲产生链球菌。变种人有明显的生态优势。 与此直接相反，用木糖醇脉冲导致对链球菌的显著抗微生物作用。变形链球菌米勒里基本上没有受到影响。 这支持了其他研究人员最近的发现，即链球菌对戊糖醇的摄取。在批量培养中，变异体建立了一个“无效循环”，导致生长抑制甚至细胞死亡。
Continuous culture is a means whereby organisms can be grown at rates approaching those occurring naturally. Moreover, the effect of adding transient excesses of various nutrients to the culture vessel ('pulsing') simulates the effect of dietary challenge on dental plaque organisms. Mixed cultures of Streptococcus mutans T8 and Streptococcus milleri B448 were grown glucose-limited in a chemically defined medium under an atmosphere of 5 per cent carbon dioxide in nitrogen, at a dilution rate of D = 0.1 h-1 and controlled pH of 7.0. The level of arginine in the medium reservoir was adjusted so that Strep. milleri predominated over Strep. mutans in a stable coexistence. After equilibration, the culture vessel was pulsed with various carbohydrates to a final concentration of 5 x 10(-2)mol/L. Samples were then taken at regular intervals and differential viable counts of Strep. mutans and Strep. milleri were done on mitissalivarius agar. Results demonstrated that pulsing with glucose, fructose, 'coupling sugar', lactose, xylose and sorbitol gave Strep. mutans a clear ecological advantage. In direct contrast, pulsing with xylitol resulted in a marked antimicrobial effect on Strep. mutans while Strep. milleri was essentially unaffected. This supports recent findings by other workers that uptake of this pentitol by Strep. mutans in batch culture sets up a 'futile cycle', leading to depressed growth or even cell death.