Combination of yeast hydrolysates to improve CHO cell growth and IgG production

Abstract

Many studies underlined the great benefits of hydrolysates used as additives in animal free media on cell culture performances. However, to precisely define hydrolysate supplementation strategies, a deeper understanding of their effect on cell growth and protein production is required. In the present study, the effect of addition of one yeast extract (YE) and two yeast peptones (named YP.A and YP.B) in a chemically defined medium was first assessed on cell culture performances. Interestingly, specific effects were found depending on the degree of degradation of yeast hydrolysates. The YE at 1 g L -1 increased the maximal cell density by 70 %, while a mixture of YE (1 g L -1 ) and YP.A (4 g L -1 ) increased IgG production by 180 %. These conditions were then evaluated on the CHO cell kinetics all over cultures. Hydrolysates extended the cell growth phase in Erlenmeyer flask and increased the maximal growth rate in bioreactor up to 20 %. Cell growth stimulation induced by hydrolysates addition was linked with energetic metabolism improvement suggesting that they promote oxidative pathway. Furthermore, hydrolysates provided an additional source of substrate that supported cell growth despite glutamine limitation.

Understanding the intracellular effects of yeast extract on the enhancement of Fc-fusion protein production in Chinese hamster ovary cell culture

“…Yeast extract (YE), as one kind of non-animal source hydrolysates, has been widely used to stimulate cell growth and heterologous protein expression in animal cells including CHO and insect cells (Mosser et al 2013;Sung et al 2004). Studies on the metabolic response and energy regulation with addition of YE had been done to investigate their functions or characteristics in recent years (Li et al 2012;Mendonca et al 2007;Mosser et al 2013).…”

“…Studies on the metabolic response and energy regulation with addition of YE had been done to investigate their functions or characteristics in recent years (Li et al 2012;Mendonca et al 2007;Mosser et al 2013). However, there is still an urgent demand in exploring the molecular mechanisms systematically.…”

“…Due to this obvious advantage, YE has been widely used in mammalian cell cultures to achieve robust culture performance with remarkable improvement. However, the impacts of YE were also observed as a variation among distinct sources of YEs or cell types (Li et al 2012;Mendonca et al 2007;Mosser et al 2013). While some reports attributed the improved cell growth and productivity to the nutritional enrichment by addition of hydrolysates (Nyberg et al 1999), some recent results proposed that Electronic supplementary material The online version of this article (doi:10.1007/s00253-015-6789-5) contains supplementary material, which is available to authorized users.…”

“…possible peptides in hydrolysates with growth-promoting, anti-apoptotic, or production-enhancing effects played the main role (Mosser et al 2012;Sung et al 2004). On the other hand, a kinetic study of Chinese hamster ovary (CHO) cells highlighted that cell growth phase extended by YE addition resulted from the TCA cycle supplement and improvement of oxidative metabolism (Mosser et al 2013). Furthermore, multivariate data analytics also showed that the catabolic pathways of amino acids (serine and glycine) in hydrolysates greatly influenced the distribution of the intracellular metabolic flux, which further correlated to cell growth improvement (Lee et al 2014).…”

The bioactivity and fractionation of peptide hydrolysates in cultures of CHO cells

“…Several studies indicate that oligopeptides are active components of yeast hydrolysate, promoting higher growth and/or productivity. Yeast extract (the water soluble component of yeast hydrolysis) promoted growth of CHO, whereas the yeast peptone component rich in oligopeptides enhanced productivity by 100% . And low molecular weight protein fractions of yeastolate enhanced the growth rate and productivity of insect cells .…”