Gibbs Energy Consumption for Biomass Yield

The minimum Gibbs energy dissipation required purely for growth, per unit biomass.
The specific rate of Gibbs energy consumption for cellular maintenance purposes.
The rate of increase of biomass concentration per unit biomass concentration per unit time.

Calculation Explanation

This calculation estimates the Gibbs energy consumed per unit of biomass produced (1/Ygx) using a thermodynamically based approach, often associated with J.J. Heijnen. It relates the observed energy consumption to the theoretical minimum required for growth (1/Ymaxgx) and the energy required for maintenance (mg) at a specific growth rate (μ).

The formula used is:
1 / Ygx = (1 / Ymaxgx) + (mg / μ)

Where:
- 1/Ygx: Gibbs energy consumption per unit biomass (kJ C-mol⁻¹ X).
- 1/Ymaxgx: Minimum Gibbs energy for growth per unit biomass (kJ C-mol⁻¹ X).
- mg: Biomass specific rate of Gibbs energy consumption for maintenance (kJ C-mol⁻¹ X h⁻¹).
- μ: Specific growth rate (h⁻¹).

This model highlights that the total energy cost includes a growth-associated component and a maintenance-related component, which becomes more significant at lower growth rates.