Question

The addition of ions and sugars added to the fermentation increases the oxygen solubility?

(a) True

(b) False

The question was asked in an interview for job.

Question is from Estimating Oxygen Solubility topic in section Mass Transfer of Bioprocess Engineering

Answer 1

Correct option is (b) False

Best explanation: Oxygen solubility is decreased by the ions and sugars normally added to fermentation media. In a typical fermentation medium, oxygen solubility is between 5% and 25% lower than in water as a result of solute effects. In simple systems, with all the components being dissolved, C0 represents the oxygen solubility and linearly decreases with increasing solute concentrations. In complex solutions with multi-phase structure an increase in C0 can be detected. It suggests that C0 consists of two components — one being oxygen solubility, the other being determined by the amount of oxygen adsorbed on the interphase and bound by macromolecules. The presence of biomass leads to a decrease in C0.