An automatic system for the assessment of complex medium additives under cultivation conditions

Complex medium additives such as yeast extract or peptone are often used in industrial cell culture processes to prolong cell growth and/or to improve product formation. The quality of those supplements is dependent on the pr eparation method and can differ from lot to lot. To guarantee consistent pr oduction these different lots have to be tested prior to use in fermentatio n processes. Because a detailed qualitative and quantitative analysis of al l components of such a complex mixture is a very difficult task, another as sessment method has to be chosen. The best way to evaluate the effect of su ch supplements is to monitor cell activity during real cultivation conditio ns with and without the added supplement lot. A bioreactor-based test syste m has been developed to determine the oxygen requirement of the cells as a response to the addition of a supplement to be tested under standardized co nditions. Investigations were performed with a mouse-mouse hybridoma cell line and ye ast extracts as an example for complex medium additives. The results showed differences in the impact between different extract lots and between diffe rent concentrations of an extract. (C) 2001 John Wiley & Sons, Inc.