Two industrial media reveal a mitochondrial disfunction in CHO cell cultures co-fed with glucose and lactic acid

Metabolomics analyses of cell culture processes can provide valuable insight into cellular physiology that can be leveraged to develop more productive processes. In this work, we applied metabolomics to interrogate CHO cell behavior in two industrial chemically-defined media in cultures co-fed with glucose and lactic acid. We previously reported that secreted acylcarnitines are indicative of altered mitochondrial metabolism when cultures are fed lactic acid and serve to maintain homeostasis between free CoA, acetyl-CoA, free carnitines, and acylcarnitines (Vappiani et al., 2021). One of the two media ("Medium B") increased significantly viable-cell count and antibody titer than Medium A. Here, we report that CHO's mitochondrial dysfunctionality based on the secretion of acylcarnitines in lactic acid-fed cultures depends on the overall medium composition. We hypothesize that in order to achieve better growth and titer, Medium B exhibited an increased oxidative phosphorylation based on the lower secretion of acylcarnitines and a differential utilization of riboflavin and thiamine, precursors of coenzymes required to enhance mitochondrial pyruvate incorporation and TCA cycle function. Therefore, our data provides further evidence that non-obvious changes to medium composition can have substantial effects on CHO-based production processes by altering the activity of oxidative phosphorylation required for the proper functioning of mitochondria but also for better antibody production.