Air Fermentation: Risks and Benefits

Many valuable biopharmaceutical and biotechnological products are produced by aerobic fermentation, which includes mammalian and microbial cell culture applications. Worldwide demand for fermentation products has been increasing steadily, and this trend is expected to continue. To improve productivity, manufacturers are trying to run high-strength broths with higher biomass levels to achieve larger product yields. Because of this trend, and the fact that eliminating oxygen starvation phases can increase bioreactor and fermenter yields, improved aeration concepts have recently been established to satisfy the additional oxygen demands of fermentation and cell culture unit operations.

Modern aeration increasingly uses enriched or pure gaseous oxygen to improve cell culture productivity. Sterilising grade gas filters that can be integrity-tested by means of a water intrusion test (WIT) are the best way to prevent spoilage of bioreactors and fermenters by organisms and contaminants in incoming and outgoing air and oxygen streams.

However, many materials, such as organic matter, plastics or metals, can potentially ignite when they come into contact with oxygen, particularly if they are also subjected to static discharges, high temperatures, pneumatic shocks or mechanical impact. In addition to the aforementioned safety aspects, oxygen or enriched oxygen gases can lead to accelerated oxidation or corrosion of component materials.