A simple thermodynamic approach for derivation of a general Monod equation for microbial growth

The Monod equation has been widely applied to describe microbial growth, but it has no any mechanistic basis. Based on the thermodynamics of microbial growth process, a general model for microbial growth was developed. The constants involved in the present model were defined with clear physical meanings. The model derived can be reduced to the Monod equation, Grau equation and Hill or Moser equation. Compared to the Michaelis–Menten constant with the equilibrium thermodynamic characteristics, it was shown that the Monod constant (Ks) has non-equilibrium thermodynamic characteristics.