Comparison of maximum isopropanol production levels by each combination of the pathway genes. ACoAAT, acetyl-CoA acetyltransferase; ACoAT, acetoacetyl-CoA transferase; ADC, acetoacetate decarboxylase; ec, E. coli; ca, C. acetobutylicum; cb, C. beijerinckii; tb, T. brockii. The error bars indicate standard deviations of at least two independent experiments.