Similarly, bacterial synthesis occurs when an reduced electron donor, often supplemented with a nitrogen source, is used and incorporated in bacterial cell biomass. Generic respiration and synthesis reactions. An electon equivalent is the amount of substance which releases 1 mol of electrons during a specified oxidation reaction. When the same electron donor is used for both energy and biomass formation, it is possible can define a ratio A as the eeq of electron donor converted to energy per eeq of cells synthesized, ignoring decay and maintenance requirements. Schematic overview of energy and material flows in microbial respiration and synthesis.
Energy flows are in red and amaterial flows are in purple.
With this framework in place one can estimate the free energy of formation during microbial synthesis. However, in some bioenvironmental processes nitrate can serve as the nitrogen source for cell synthesis. Conceptual definitions of basal metabolism and yield coefficients to model substrate utilization rates on a mass basis. This model can be re-cast in terms of electron equivalents of cells and substrates. Using these formulae it is possible to calculate both types of yield coefficients for microbial synthesis from different substrates.