Meat production contributes significantly to greenhouse emissions. For instance, when one kilogram (2.2 lbs) of beef up is produced, about 60 kg (~132 lbs) of greenhouse gases are released.
Instead of slaughtering animals, if we start producing meat in a lab from cultures of stem cells, greenhouse emissions could go down drastically.
A shocking report from the University of California, Berkeley suggests that cultivated meat could reduce emissions by 96 percent. However, currently, the biggest challenge with cultivated or lab-grown meat is that it’s so expensive that most people can’t afford it.
A new study from Tufts University researchers reveals an interesting solution to this problem.
Why cultivated meat is so expensive?
Compared to the meat that comes from slaughtering animals, lab-grown meat possibly requires 99 percent less land and 80 to 90 percent less water, yet it is highly expensive because of special ingredients known as growth factors. These are signaling molecules composed of recombinant proteins.
They trigger the growth and multiplication of animal cells, playing a crucial role in the cell culture process, ensuring that the cells develop into the desired tissues that make up meat. Without adding this ingredient, one can’t turn cells into meat.
However, the price for just one gram of a growth factor can range from a few hundred dollars to millions, depending on the type, and they are manufactured and sold by big industrial suppliers.
This is why, “Growth factors contribute to a majority of the cost of production for cultivated meat (up to or above 90%). Since they don’t last long in the cell culture media, they also have to be replenished every few days. This limits the ability to provide an affordable product to consumers,” the researchers note.
The researchers from Tufts University modified bovine muscle cells such that the cells were able to produce fibroblast growth factors (FGF) on their own, eliminating the need to purchase growth factors from external sources.
“All muscle cells and many other cell types typically rely on FGF to grow. What we did was engineer bovine muscle stem cells to produce these growth factors and turn on the signaling pathways themselves,” Andrew Stout, lead study author and Director of Science, Cellular Agriculture Commercialization Lab at Tufts University.
Moreover, since FGF is required for the growth of not just bovine but almost all kinds of muscle cells, this approach can also be applied to reduce the cost of pork, chicken, and other types of lab-grown meat as well, according to the researchers.
The power of gene editing
Cultured meat is produced in bioreactors, large vessels containing nutrients, salts, proteins, and an environment that promotes the growth of animal stem cells. When growth factors are added to the medium inside a bioreactor, it introduces foreign genes into the animal cells.
These genes stimulate the growth and multiplication of the stem cells. However, the method proposed by the study authors doesn’t rely on foreign genes for turning cells into meat.
Instead, they use gene editing to activate specific genes within the original stem cells that can release growth factors.
“In this strategy, we’re not adding foreign genes to the cell, just editing and expressing genes that are already there,” Stout said.
Since regulatory bodies such as USDA are more stringent for food items containing foreign genes rather than those subjected to native gene editing. This method could also make it simpler and faster for lab-grown meat to receive regulatory approval.
However, this gene-editing-based meat cultivation approach is not perfect. It also has some limitations.
“While we significantly cut the cost of media, there is still some optimization that needs to be done to make it industry-ready. For instance, we did see slower growth with the engineered cells, but I think we can overcome that,” Stout added.
The researchers will continue their work to further improve their meat cultivation method.
The study is published in the journal Cell Reports Sustainability.
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