Microcalorimetric study of the effect of temperature on microbial activity in soils

The effect of temperature on the microbial degradation of glucose in soil was studied in a conduction-type microcalorimeter. The microbial growth constant, mu, was calculated from the heat evolution associated with the degradation of carbon source, and the power-time curves recorded at different temperatures. The activation energy was obtained from an Arrhenius-type equation and was found to be 39.57 kJ mol(-1). Based on the fact that the pattern of bacterial growth is similar to the transition-state theory for chemical process, values of activation entropy, Delta S-not equal, and activation free energy, Delta G(not equal), were calculated. These data can be very useful when studying bacterial growth thermodynamic properties in soil. (C) 1997 Elsevier Science B.V.