from 6.5 to 5.5 unitless
||Budding yeast Saccharomyces cerevisiae
||Karen van Eunen & Barbara M. Bakker, The importance and challenges of in vivo-like enzyme kinetics, Perspectives in Science, Volume 1, Issues 1–6, May 2014, Pages 126–130, link pdf link p.128 right column 2nd paragraph
||Kresnowati MT, Suarez-Mendez CM, van Winden WA, van Gulik WM, Heijnen JJ. Quantitative physiological study of the fast dynamics in the intracellular pH of Saccharomyces cerevisiae in response to glucose and ethanol pulses. Metab Eng. 2008 Jan10(1):39-54. DOI: 10.1016/j.ymben.2007.10.001PubMed ID18054509
||P.128 right column 2nd paragraph: "Intracellular pH is recognized as one of most important factors that affects enzyme activities. To complicate matters, it may change rapidly upon a change in the environment. For instance, the intracellular pH of yeast drops from 6.5 to 5.5 upon a glucose or ethanol pulse to glucose-limited chemostat cultures (primary source). To mimic this in vitro, it is required to measure the intracellular pH accurately under conditions of interest."