The climate impact and land use of cultivated meat: Evaluating agricultural feedstock production

existing novel food guidelines. Post-Brexit, the UK is creating specific regulations, and the US is coordinating between the FDA and USDA. Canada and Brazil are also progressing in their regulatory approaches [56]. 2.1 Technical background of CM production CM production encompasses various stages: cell isolation, cell expansion, differentiation, bio- reactor utilization, and harvesting. Initiated by extracting muscle or fat cells from animal tis- sues, these cells are nurtured in a nutrient-dense culture medium. Following sufficient proliferation, these cells undergo differentiation into muscle cells. Subsequently, this tissue is matured in a bioreactor until it reaches an optimal state for harvesting and processing into meat products. Preliminary prototypes spanning beef, pork, and poultry highlight the potential of this approach [37, 50, 56]. Culture media, instrumental in in vitro meat production, present economic and technical challenges. Current formulations, although general, necessitate tailoring for specific cellular metabolic states. Although fetal bovine serum, a meat industry byproduct, is commonly used in cell culture media, serum-free alternatives are under investigation to alleviate associated eth- ical concerns [47, 57]. Moreover, innovations are imperative in cellular modulation. These could be reached by physical and chemical conditioning, optimized substrate elasticity, and nutrient diffusion in expansive tissues [29, 32, 58]. Formulating cell media entails sourcing from diverse origins and processes. Core compo-

nents include glucose, amino acids, vitamins, and trace elements crucial for optimized cell growth and yields. O’Neill (2021) [46] suggests incorporating renewable feedstocks like ligno- cellulosic hydrolysates into media formulations for environmental sustainability. Vergeer’s & Risner’s LCAs emphasizes the role of eco-friendly practices in media formulation, touching on issues such as the environmental ramifications of antibiotics and the strain from glucose pro- duction [58, 59]. Research supports cell media derivation from plants like soy and maize for sugars and amino acid extraction, alongside utilization of precision fermentation or biotech- nological processes [40, 41, 50, 60–62]. This study accentuates plant-based media composition, considering its implications on agriculture and land use. Cell metabolism encapsulates the myriad chemical reactions essential for cellular suste- nance and growth, including nutrient breakdown, molecular synthesis, and waste elimination. The vital components for these reactions range from glucose, amino acids, and vitamins to oxygen and growth factors like hormones. To evaluate the demand of cells for efficient growth of CM, we assumed the following metabolism reaction taken from Humbird (2021) [37]: 0:147 Glc þ 0:378 O2 þ 0:007 Arg þ 0:004 Cys þ 0:022 Gln þ 0:003 His þ 0:007 Ile þ 0:010 Lys þ 0:002 Met þ 0:005 Phe þ 0:009 Thr þ 0:002 Trp þ 0:005 Tyr þ 0:010 Val þ 0:013 Ala þ 0:006 Asn þ 0:008 Asp þ 0:011 Gly þ 0:011 Leu þ 0:007 Pro þ 0:010 Ser ! ð1Þ DCMa þ 0:005 Glu þ 0:004 NH3 þ 0:041 Lac þ 0:455 CO2 þ 0:613 H2O

In the fed-batch process as assumed in Humbird (2021) [37], cells are cultivated in a nutri- ent-rich medium, replenished periodically. Contrary to perfusion cultures, where nutrients are provided and waste is removed continuously, with the fed-batch process the medium is depleted as cells reach certain densities. The fed-batch technique is cheaper, but cell growth may be limited to a certain extent [37, 43]. For CM to be widely accessible, scalable production is vital. Humbird (2021) [37] expounds on the challenges, emphasizing bioreactor issues during fed-batch operations. Compared to PLOS ONE Evaluating agricultural feedstock for cultivated meat PLOS ONE | https://doi.org/10.1371/journal.pone.0316480 January 22, 2025 4 / 27