ATP metabolism in Streptococcus mutans

变形链球菌中的 ATP 代谢

• 批准号: 02670832
• 负责人: KODAMA Takao
• 金额: $ 1.34万
• 依托单位: OKAYAMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02670832/
• 关键词: Streptococcus mutans; ATP generation; ATP utilization; energy metabolism; H^+-ATPase

(1) Streptococcus rattus, a serotype b strain of mutants streptococci, was grown in an anaerobic gulcose-limited chemostat to determine the molar grown yield of glucose, the maximum growth yields and maintenance coefficients form glucose uilizition and calculated ATP generation as a function of pH.Also examined was the presence of an F_1F_0-type H^+-ATPase in cells grown under acidic conditions and in cells grown at neutral pH.The results suggest that the organism responds and adapts to environmental acidification by sacrificing some energy cost in terms of both the efficiency of glucose utilization to generate ATP and the extra maintenance required to continue biomass production ad efficiently as under neutral pH.(2) Kinetic measurements were made of the cellular responses of S.mutans FA-1 to ethanol. Oxygen was absolutely required for acid production from ethanol, which elicited a marked increase in the intracellular ATP concentration (ATP_1) from a starved level to a steady level which was held constant as long as oxygen was present in the medium. Once oxygen was exhausted, ATP_1 returned to the starved level without delay. Both the steady ATP_1 and the rate of accompanying oxygen consumption were functions of the ethanol concentration.

(1) 大鼠链球菌 (Streptococcusrattus) 是突变链球菌的血清型 b 菌株，在厌氧葡萄糖限制恒化器中生长，以确定葡萄糖的摩尔增长产量、最大生长产量和葡萄糖利用的维持系数，并计算 ATP 生成量与pH。还检查了酸性条件下生长的细胞和中性条件下生长的细胞中 F_1F_0 型 H^+-ATPase 的存在pH值。结果表明，生物体通过牺牲一些能量成本来响应和适应环境酸化，这些能量成本包括葡萄糖利用产生ATP的效率以及在中性pH下有效地继续生物质生产所需的额外维护。(2)对变形链球菌 FA-1 对乙醇的细胞反应进行了动力学测量。乙醇生产酸绝对需要氧气，这会导致细胞内 ATP 浓度 (ATP_1) 从饥饿水平显着增加到稳定水平，只要培养基中存在氧气，该浓度就保持恒定。一旦氧气耗尽，ATP_1立即恢复到饥饿水平。稳定的 ATP_1 和伴随的耗氧速率都是乙醇浓度的函数。