Oxygen availability for bacterial growth with a flow microcalorimeter

The enthalpy change associated with aerobic growth of E. coli K₁₂ on minimal media with succinic acid as sole carbon and energy source, determined by flow microcalorimetry (with aerobic mixing cell) was 733.01±15.32 kJ·mol^-1. Molar growth yield was 39.6±1.2 g·mol^-1. When the microcalorimetric growth was limited by oxygen supply, the power-time curve was altered and the total heat evolved was less than the enthalpy change. The maximum thermal output corresponding to a fully aerobic growth in the calorimetric cell was 1.89×10^-3 W·ml^-1. Thus, the oxygen uptake rate was about 0.39 ml O₂·h^-1·ml^-1.