Application Note: Control of Fermentation Processes

Fermentation is the process by which living organisms are cultured or grown to produce a specific product. The products can be as simple as baker's yeast and alcohols, or as complex as therapeutic proteins, antibiotics, enzymes, and genetically engineered materials. Regardless of the end product, fermentation reactions must be carefully monitored to gauge the health of the culture, and to determine when the culture can be harvested. Since these are living organisms, the levels of oxygen and carbon dioxide in the off-gases can be used to follow the progress of fermentation. The ratio of carbon dioxide to oxygen is called the respiratory quotient (RQ) and is the prime indicator of culture health. While these measurements can be made by several techniques, the most accurate RQ determination requires complete knowledge of the flow of gases into and out of the reactor. By virtue of its ability to measure all of the gases entering and exiting the reactor, the ProLine process mass spectrometer provides a highly refined control signal to maximize culture health and productivity.