Microcalorimetry was used to study the microbial degradation of glucose in soil. Relationships between heat evolution and the viable cell counts permit the quantification of kinetic parameters for microbial growth in soil, such as Monod’s substrate constant, K(s) = 1.62 +/- 0.08 mM, and the maximum microbial growth rate constant, mu(max) = 0.26 +/- 0.01 h-1.