Using Transgenic Rice As a Plant Molecular Foundry for the Production of Media Components for Cultivated Meat

Transferrin is a glycoprotein mainly found in blood plasma and used as an essential ingredient in different types of cell culture media because of its crucial role in iron uptake, regulating cellular transport, and utilization. Cultivated meat is a rapidly advancing technology that produces meat products by proliferating and differentiating animal stem cells in bioreactors, avoiding conventional live-animal farming. One of the major bottlenecks has been identified as the cost of media or media components. The focus of this study is the design of a large-scale transferrin production facility from transgenic rice seeds to demonstrate a possible techno-economic path towards scaling-up of media components to use in the production of cultivated meat. Rice has an advantage over other hosts because, as a food product, it is generally recognized as safe (GRAS), and rice biomass may be safely included in cultivated meat media or even used to supplement the texture or taste profile. We assumed an expression level (titer) of 10 g transferrin/kg rice (1% seed dry weight). We also assumed that the recombinant transferrin was extracted with saline buffer and then purified by one-step anion exchange chromatography to about 95% purity and a production of 20,500 kg transferrin/year. Our preliminary study demonstrates the feasibility of a safe, and potentially much lower-cost alternative, to human or animal plasma-derived transferrin for use in cultivated meat production.