Sterile Bioreactor Feeding

Colder Products Company's bioprocessing connections have been used in bioreactor and fermentor feed applications for over 15 years. Colder helps manufacturers ease the transition between stainless processing equipment and disposable systems with the use of MPC and MPX couplings and more recently with the introduction of Steam-Thru and SaniQuik Connections.

Culture media are based on powder mixtures of simple sugars, salts, amino acids and vitamins. Once media powder is hydrated and liquid supplements are added, the final liquid media is filter sterilized and stored in glass or plastic bottles, stainless steel storage vessels or single-use flexible bag systems. Standard strategies for feeding media into bioreactors include batch, fed-batch and continuous perfusion.

In batch processes, a sterilized bioreactor is filled to its working volume with sterile media prior to inoculation with a specific cell culture. Once inside the bioreactor, cells utilize the nutrients in the media to grow, multiply and produce proteins. After 1 to 14 days of growth, the culture has consumed most of the available nutrients and cells and/or proteins are harvested in one batch.

In fed-batch processes, a bioreactor is partially filled with media prior to inoculation.  Additional fresh media is fed into the bioreactor to replace consumed nutrients as cells grow. This typically extends culture duration and increases yields. Harvests are usually performed in a single batch.

Continuous perfusion processes are designed to extend culture duration by maintaining stable levels of nutrients. Cultures begin similar to the fed-batch processes. After the density of the cells increase, fresh media is slowly fed into the bioreactor while harvest is simultaneously collected. Continuous perfusion culture may remain active for months.