A circular cell culture system using microalgae and mammalian myoblasts for the production of sustainable cultured meat.

For sustainable production of cultured meat, we propose a novel circular cell culture (CCC) system in which microalgae are used as nutrient supply for the mammalian cell culture and as a waste-medium recycler. Chlorococcum littorale, RL34 hepatocytes, and C2C12 myoblasts were used as cell sources for microalgae, growth factor-producing cells, and muscle cells, respectively. In the first cycle, C2C12 cells were amplified 4.0-fold after 48 h of culture in an RL34 cell-conditioned medium. In the second cycle, C2C12 cells were cultured in the C. littorale culture waste medium to which the C. littorale-derived nutrients were added. The proliferation rates of C. littorale and C2C12 and the nutrient extraction efficiency from C. littorale were the same in the first and second cycles. Therefore, this CCC system, which works without additional grain-derived nutrients and animal sera, will help drastically reduce environmental load, resource/energy consumption, and costs in future cultured meat production.