Meat without slaughter: '6 months' to bio-sausages-The New Scientist Mag

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Meat without slaughter: '6 months' to bio-sausages
31 August 2011 by Andy Coghlan

Who needs whole animals when you can grow burgers and sausages from their cells alone, in the lab - and do your bit for the environment too

FIRST we hunted animals for their meat. Then we developed ways to raise them on farms. Now we are on the verge of the next breakthrough. Within months labs could be growing synthetic meat for the table - and not just the usual steaks and burgers either. Meat from exotic animals could one day widen our culinary choices, for those adventurous enough to try.

This week, researchers met in Gothenburg, Sweden, to plot out a path towards meat without slaughter. The idea of pain-free meat has been bandied about in the past decade, but several false dawns later one fact remains unchanged. "No one has produced in vitro meat yet," says Julie Gold of Chalmers University of Technology in Gothenburg, who helped organise the meeting.

The first lab-grown sausage might be just six months away, though, according to Mark Post of Maastricht University in the Netherlands - a major pioneer and champion of the technology. Post has experimented mainly with pig cells and has recently developed a way to grow muscle under lab conditions - by feeding pig stem cells with horse fetal serum. He has produced muscle-like strips, each 2.5 centimetres long and 0.7 centimetres wide.

Post makes sure his tissue strips receive daily exercise to give them the same constitution as real muscle. He anchors them onto Velcro before stretching the cells away from the surface. Even so, the strips looks anaemic and unappetising. "It's white because there's no blood in it, and very little myoglobin, the iron-bearing protein," he says. "We are looking at ways to build up the myoglobin content to give it colour."

With funding from an unnamed philanthropist, Post is ready to extend the work to cow cells. "I'm hopeful we can have a hamburger in a year," he says.

But why stop there? "I believe that we can eat all kinds of previously very rare meat," says Stellan Welin, a bioethicist at Linköping University in Sweden and another organiser of this week's meeting. He says our meat choice is largely governed by the animals that have proved easy to domesticate, not necessarily those with the tastiest meat. With synthetic meat, these rules no longer apply. Since all you need to start the process of production are muscle stem cells, these could be obtained from rare or exotic animals relatively easily. Because that could be done without killing the animals, some of the ethical questions posed by panda burgers could be sidestepped, Welin says.

One thing slowing Post's progress is the limited ability of pig muscle stem cells to multiply in culture. They divide only 20 to 30 times, forcing Post to go back regularly and extract fresh supplies from pig tissue.

Bernard Roelen of Utrecht University in the Netherlands, another Gothenburg attendee, may be able to help. He is extracting different types of stem cells from pig muscle to identify those capable of multiplying for months. In 2008, he isolated a subset of stem cells called muscle-derived progenitor cells (MDPCs) which might be up to the task. "If we start with 1000 cells, after three months we have billions upon billions," he says (Journal of Cellular Biochemistry, DOI: 10.1002/jcb.21921).

Even if Post does successfully grow a lab burger in the next 12 months, will we want to eat it? Gold points out that no one knows what the clumps of muscle cells taste like. Strict regulations prevent the consumption of lab-grown tissue fed on calf fetal serum because of a very low risk that it may contain prions or other harmful contaminants. Feeding synthetic meat on animal products also defeats the purpose of meat without slaughter.

Joost Teixeira de Mattos at the University of Amsterdam, the Netherlands, and others are attempting to develop feed based on cyanobacteria instead, which produce extracts rich in the amino acids, sugars and fats that the animal cells require.

Researchers know very well that their work can be regarded as unnatural, and consequently struggle to attract funding. A notable exception is $1 million offered by PETA (People for the Ethical Treatment of Animals) for the first commercial synthetic meat. Welin points out that ironically, the livestock in vitro meat could replace is often kept in unnatural conditions and dosed with hormones or antibiotics.

Strengthening the moral case for synthetic meat is its low impact on the environment. Hanna Tuomisto at the University of Oxford estimated the resources needed to grow 1000 kilograms of lab meat by extrapolating from the demands on energy, water and land made by industrial-scale, cellular-based pharmaceuticals operations. She compared those results with the environmental costs of generating 1000 kilograms of beef, lamb, pork and poultry (see diagram). "The impacts are so much lower," she says. For instance, cultured meat will require 99 per cent less land than beef farming (Environmental Science and Technology, DOI: 10.1021/es200130u).

Welin says the results further demonstrate that the line between natural and unnatural is not as clear-cut as it might appear. "Making meat [in the laboratory] will give much more space to nature," he says. "It will be interesting to see how the Green political parties react to this."