Table 6. Concentration of metabolites of glycolysis and the TCA cycle in wild-type cells in the absence or presence of 10 mM KCl^a.

Metabolite	Concentration (pmol/109 cells)b				Ratioc
	Glucose	Glucose + K+	Malate	Malate + K+	Glucose K+/no K+	Malate K+/no K+
Glycolysis:
Glucose 1-phosphate	113 ± 13	N.D.	75 ± 6	N.D.	low	low
Glucose 6-phosphate	198 ± 47	759 ± 93	93 ± 8	558 ± 20	3.83	6.02
Fructose 6-phosphate	N.D.	141 ± 5	77	132 ± 6	high	1.71
Fructose 1,6-diphosphate	514 ± 134	468 ± 60	528 ± 103	113 ± 11	0.91	0.21
3-Phosphoglyceric acid	N.D.	781 ± 56	N.D.	N.D.	high	N.D.
Dihydroxyacetone phosphate	N.D.	414 ± 73	107	N.D.	high	Low
Glycerol 3-phosphate	N.D.	201 ± 30	111 ± 12	78 ± 8	high	0.71
6-Phosphogluconic acid	N.D.	N.D.	N.D.	213 ± 28	N.D.	High
Lactic acid	6500 ± 650	5850 ± 1310	5400 ± 1,040	7,020 ± 380	0.90	1.3
TCA Cycle:
Acetyl CoA	113 ± 22	61 ± 8	22	N.D.	0.54	low
Citric acid	338 ± 59	2170 ± 180	383 ± 66	2900 ± 270	6.41	7.58
2-Oxoglutaric acid	N.D.	4830 ± 970	714	4420 ± 830	high	6.17
Succinic acid	513	1750 ± 640	2250 ± 250	4010 ± 750	3.40	1.79
Fumaric acid	N.D.	N.D.	3050 ± 840	3770 ± 1100	N.D.	1.23
Malic acid	691 ± 102	755 ± 156	51200 ± 5200	53300 ± 4100	1.09	1.04

^aMetabolites with statistically significant differences (p < 0.05; Welch’s t-test) between the presence and absence of K⁺ in at least one substrate (glucose or malate) are shaded orange, as are the respective concentration values and ratios.

^bMean ± SE of 3–5 experiments. N.D. = below detection limit. Metabolite concentration can also be expressed in μM assuming an intracellular volume of 1 μl/10⁹ cells.

^c A “high” or “low” ratio indicates that the metabolite was not detected in the substrate only or in the substrate + K⁺ condition, respectively, but was detected in the other condition.