Monod equation

The Monod equation is a mathematical model for the growth of microorganisms.

It is named for Jacques Monod (1910–1976, a French biochemist, Nobel Prize in Physiology or Medicine in 1965), who proposed using an equation of this form to relate microbial growth rates in an aqueous environment to the concentration of a limiting nutrient.

They will differ between microorganism species and will also depend on the ambient environmental conditions, e.g., on the temperature, on the pH of the solution, and on the composition of the culture medium.

In some applications, several terms of the form [S] / (Ks + [S]) are multiplied together where more than one nutrient or growth factor has the potential to be limiting (e.g. organic matter and oxygen are both necessary to heterotrophic bacteria).

When the yield coefficient, being the ratio of mass of microorganisms to mass of substrate utilized, becomes very large, this signifies that there is deficiency of substrate available for utilization.