The validity of the application of simple kinetic analysis to heterogeneous microbial populations1

It is shown by use of a mathematical model that heterogeneous populations do not adhere to the Michaelis and Menten equation; at low substrate concentration, observed rates are higher than predicted ones. The discrepancy between observed and predicted values increases as the population becomes more diverse. If kinetic analysis based on the Michaelis and Menten equation is used to determine the rate of turnover of substrates in natural waters, the rate may be underestimated unless measurements are made at very low added substrate concentrations.