期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1981
卷号：78
期号：10
页码：6271-6275
DOI：10.1073/pnas.78.10.6271
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The intracellular pH of Escherichia coli cells, respiring on endogenous energy sources, was monitored continuously by 31P NMR over an extracellular pH range between 5.5 and 9. pH homeostasis was found to be good over the entire range, with the data conforming to the simple relationship intracellular pH = 7.6 + 0.1(external pH - 7.6) so that the extreme values observed for intracellular pH were 7.4 and 7.8 at external pH 5.5 and 9, respectively. As well as inorganic phosphate, we employed the pH-sensitive NMR probe methylphosphonate, which was taken up by glycerol-grown cells and was nontoxic; its pKa of 7.65 made it an ideal probe for measurement of cytoplasmic pH and alkaline external pH.
