Whether you call it clean meat, lab meat, cultured meat, or cultivated meat, this type of animal cell culture product might transform the traditional meat processing capacity over the next several decades. The clean meat industry has been built on recent advances in cell biology and biomanufacturing and there are now several dozen companies—mostly young start-ups—vying to satisfy the world’s growing demand for meat.  However, the growth of this industry is not without its economic skeptics, due in large part to the high manufacturing costs of clean meat. One of the primary cost drivers is the cell culture media. Traditional approaches to culturing have utilized fetal bovine serum (FBS) as a growth supplement. FBS can be costly, variable in its composition, and not sustainable because it is an animal-derived component.

In a new study, a team at Maastricht University, led by one of the co-founders of Mosa Meat, recently reported on the potential to avoid all serum supplements when growing bovine myoblasts. Bovine myoblasts are a typical cell type used to produce red meat-like products. Traditionally, bovine myoblasts are cultured in advanced DMEM media with 20% FBS and 10% horse serum with antibiotics. The research team tested if chemically-defined media alone or with alternative supplements could be as effective as serum-supplemented media to grow primary bovine myoblasts without antibiotics. For all experiments, the cells originated from the skeletal muscle of a Blanc Bleu Belge cow.

First, the team investigated if the presence or absence of antibiotics (1% PSA – penicillin/streptomycin/amphotericin-B) had an impact on cell proliferation. In serum-containing and serum-free media, the lack of antibiotics led to a greater than 20% increase in cell growth. In another study, none of the commercial serum-free media platforms resulted in sustained cell growth that exceeded the serum-containing growth media. In fact, only three serum-free media types resulted in noticeable cell growth over the six-day culture.

Additionally, the serum-free media showed the highest cell growth when commercial serum-free growth supplements added to them. Of the four cell media compositions tested, only the combined media of half DMEM with half fibroblast basal media (FBM) containing a lipoprotein supplement showed favorable proliferation of bovine myoblasts. However, despite the increased growth, the lipoprotein supplement changed the phenotype of some myoblasts to an undesirable adipocyte-like cell with fat vacuoles. It’s worth noting that since the lipoprotein supplement was derived from a serum-based cholesterol concentrate, it is not sustainable so it’s unsuitable for long term use. When the growth factors FGF-2, EGF, IGF, and insulin were added to this mixed media, the cell growth taken at both days four and six were at least doubled compared to their absence in the supplemented media. These four growth factors were selected after a previous study added them to DMEM to grow chick myoblast cells with high proliferation.

The proteins, growth factors, cytokines, cholesterol, and fatty acids in serum allow for broad adoption across various cell culture applications. In this study, seven commercial serum-free media formulations and three supplements were tested as potential replacements to serum-supplemented media for bovine myoblast proliferation. A few combinations of media and supplements allowed for fast cell proliferation.

More investigation is necessary to determine if a serum-free and animal-free media mixture can provide similar productivities to the conventional approaches. Meat consumption is expected to increase over 70% by 2050. If clean meat is going to be a real player in satisfying the worldwide demand for meat, we will need to see an acceleration of studies like this.  As investment in new sustainable food companies continues to soar, there will be growing pressure to find a sustainable cell media system to maximize productivities that allow clean meat to become an affordable option for customers.

By, Glenn A. Harris