Table 1. Bioenergetic balances suggest energy conservation under EET conditions occurs via substrate-level phosphorylation.

The reactors contained 20 µg/mL of DHNA and mannitol as the electron donor. Balances were calculated with data obtained by day four from Figure 5. See also Supplementary file 1. SLP stands for substrate-level phosphorylation. Y_fermentation refers to the total fermentation products obtained (see Supplementary file 1) per mol of sugar consumed. Y_mannitol is the ATP produced from the total fermentation products per mol of sugar consumed, and Y_ATP is the dry weight measured per mol of ATP produced from fermentation products.

	NADH consumed*	Calculated ATP†(from metabolites)	Biomass yield	Yfermentation	Ymannitol	YATP
Units	mM	mM	g-dw/mol-mannitol	mmol product/mmol-mannitol	mol ATP/mol mannitol	g dw/mol ATP
EET	6.44 ± 0.48 via anode16.69 ± 2.72 via SLP	16.6 ± 1.5	4.85 ± 0.33	1.53 ± 0.13	1.59 ± 0.13	3.09 ± 0.36
OC	5.51 ± 0.97 via SLP	5.7 ± 0.6	7.21 ± 1.41	0.87 ± 0.09	0.89 ± 0.09	8.06 ± 0.86

^*Calculated based on production of 3 mol of NADH produced per mol of mannitol, 1 mol of NAD⁺ per lactate, 2 mol of NAD⁺ per ethanol, 2 mol of NAD⁺ mol per succinate produced and 0.5 mmol of NAD⁺ per mol of electrons harvested on the anode.

^†Calculated based on production of 1 mol of ATP per lactate, 2 mol per acetate, 1 mol per ethanol, and 3 mol per succinate produced.