Characterization of chromatographic yeast extract fractions promoting CHO cell growth

Background Many studies underline the great benefits of yeast extracts (YE), used as supplements in animal free culture media, on cell growth and recombinant protein production [1,2]. Nevertheless, their unknown composition and batch-to-batch variability of commercial YE remain constraints for industrial processes [3,4]. Consequently, the identification of bioactive YE molecules is challenging for process reliability. The main strategy to respond upon this problem is to fractionate the extract and then to characterize the fractions. So far, several fractionation processes such as ultrafiltration [5], gel filtration chromatography [6] or alcoholic precipitation [7] have been investigated. These studies suggested that the active components were mainly small molecules (< 1000 Da). But, the other physico-chemical properties of YE components have been poorly studied until now. In regards of this statement, it is proposed to get better knowledge of the YE molecules leading to an improvement of CHO cell growth, by implementing various chromatographic fractionation processes.