Never let me down: Optimizing performance of serum free culture medium for bovine satellite cells

Abstract

Cultivated meat may be a more ethical, environmentally friendly, antibiotic-free meat alternative of the future. As of now, one of the main limiting factors for bringing cultivated meat to the market is the high cost of the cell culture media and their great dependency on serum albumins, production of which is predicted to become a major bottleneck of this industry. Here, using bovine muscle stem cells (BSC) we optimized B8/B9 medium - one of the well-established serum free, fully defined medium compositions available for purchase or for preparation in-house. We show several combinations of the growth factors/myokines/hormones, which were able to substantially increase BSCs proliferation rate, as well as treatment schemes allowing for five to ten times lower concentrations of signaling molecules for the same effect. Additionally, we identified several food grade, low-price medium stabilizers, exhibiting comparable or even superior stabilization of the B8 medium in short-term cultivations, as compared to recombinant human serum albumin (HSA). DoE aided in identifying the best cultivation conditions. Other satellite cells (porcine, chicken and fish) were grown in several final cell culture medium compositions, showing significant cell-line specific differences in performance. Also, the proliferation and yield of CHO cell line, which is relevant e.g. for the production of growth factors, was also successfully increased using our stabilization approach. We conclude that stabilizers tested here can act as versatile low-cost medium additives, partly by prolonging the half-life of growth factors. Thus, we provide an alternative to HSA, enabling up to an overall 73% reduction of medium price.