Calorimetric analysis of Escherichia coli in continuous culture

The heat evolution rate was measured in continuous culture of Escherichia coli k-12 on glucose-limiting medium. The specific heat production rate based on the dry cell mass increased in proportion to increase of dilution rate. The specific heat production rate based on a viable cell increased nonlinearly because the cell size varied in each dilution rate. Several thermochemical data were calculated for each dilution rate from the stoichiometric equation which was derived from elementary analysis of the cells. Growth yields based on energy measured directly was found to be less influenced by dilution rate than the growth yield based on consumed glucose. This suggested that the energy efficiency of utilization of catabolic energy for anabolism was almost constant.