Carbon balance was calculated for each replicate as the molar sum of the products (increases in acetic acid, 1,2-propanediol, and ethanol) divided by the decrease in molar
concentration of lactic acid substrate and multiplied by 100 to be expressed as a percent. It was assumed that for each mole of lactic acid converted to acetic acid, 1 mol of
carbon dioxide was formed (CO2 not quantified).