Intracellular product recycling in high succinic acid producing yeast at low pH

Table 3 Thermodynamic comparison of different scenarios (1) Equilibrium of Mal/Pi transport (2) Derived from the assumption of oxidative fumarase in the mitochondria (Mal/Fum = 3.5)

	Mal/Pi at equilibrium		Mitochondrial fumarase in oxidative direction
	Conc. ratio (M/C)	Cytosolic amount (%)	Conc. ratio (M/C)	Cytosolic amount
Malate	9.83	50	0.236	98.1%
Succinate	9.59	51
Fumarate	9.97	50	Inf	0
Citrate	25.51	28.1	0.612	93.9%
Isocitrate	25.41	28.2	0.610	93.9%
aKG	9.96	50.1	0.239	97.6%

The equilibrium calculations depend on assumptions on the electrochemical potential (pmf = −180 mV), the pH difference (ΔpH = 0.5) and volume distribution (cytosol 70%, mitochondria 7%)

ISSN: 1475-2859