Scientists turn stem cells into pork

By MARIA CHENG, Physorg.com, January 15, 2010

Scientists at the Eindhoven University of Technology in the Netherlands announced today creation of pig muscle from stem cells that one day may serve as a new food source.  Although the Dutch scientists have been growing pig cells since 2006, they believe that their recent findings bring them closer to actual tissue that can be consumed by humans.

"If we took the stem cells from one pig and multiplied it by a factor of a million, we would need one million fewer pigs to get the same amount of meat," said Mark Post, a biologist at Maastricht University who is involved in the In-vitro Meat Consortium, a group of Dutch academic institutions that are collaborating at developing edible products using cell culture technologies. 

"Artificial" meat is grown in the laboratory using tissue culture techniques that have been available for decades.  This involves providing the cells with a nutrient mixture that resembles the natural environment in the body.  While it has been previously known that cells can be grown outside of the body and that hypothetically enough animal cells could be made to generate a tissue that could be large enough to be eaten, the problem historically has been that muscle cells do not multiply to the extent necessary.  Muscle and other cells typically reach a limit of multiplication outside of the body, called the Hayflick limit, after which they can no longer be expanded.  This problem was solved in part by the use of muscle stem cells.  Many types of stem cells express the enzyme telomerase which allows the cells to make copies of themselves with having to abide by the Hayflick limit. 

Implications of artificial meat could be tremendous.  From a medical perspective, cells could be made that possess specific characteristics, such as reduced fat, or enhanced concentration of nutrients.  Although it is possible to create whole animals through genetic engineering, such as transgenic pigs, the ability to precisely control the genetic manipulation is much higher when you are dealing with muscle stem cells as opposed to a whole animal. 

One interesting implication of artificial meat is the impact it would have on the environment.  Oxford University's Dr. Hanna Tuomisto, an expert on environmental impact of food production stated that switching to lab-produced meat could theoretically lower greenhouse gas emissions by up to 95 percent. Both land and water use would also drop by about 95 percent, she said.

"In theory, if all the meat was replaced by cultured meat, it would be huge for the environment," she said. "One animal could produce many thousands of kilograms of meat." In addition, lab meat can be nurtured with relatively few nutrients like amino acids, fats and natural sugars, whereas livestock must be fed huge amounts of traditional crops.

Unfortunately, using present tissue culture conditions the cost to make one strip of bacon would be approximately $10,000 stated one industry expert.  Thus while the technology exists, feasible implementation still seems far away using technologies available today.