Carbon balance.

Carbon balances of the three strains calculated at the end of the batch experiments for each strain separately and showing the mean values including the standard deviation of the mean, indicating carbon use for different metabolites produced during cultivation. The elemental formula of E. coli was taken from literature [28]. Metabolites were measured in the supernatant (acetate, formate, pyruvate, or lactate) or by off-gas analysis (carbon dioxide).