Meat reared in fish tanks?

Boundaries of science were pushed further recently when scientists, trying to create alternative food sources for astronauts, revealed that we could grow meat on demand, without slaughtering fish or animals, the New Scientist reports this week.

Scientists trying to create alternative food sources for astronauts believe we could grow meat on demand, without slaughtering fish or animals, the New Scientist reports this week.

In a bid to make a simple source of nutritious food for long-distance space travellers, scientists at Touro College in New York have managed to make slices of fish grow bigger. Their achievement holds out the prospect of growing meat in industrial quantities from the muscle cell lines of various animals or fish, the report continues.

"This could save you having to slaughter animals for food," said project leader Morris Benjaminson, a bioengineer and veteran of a number of NASA projects on recycling waste onboard spacecraft.

Benjaminson is working on more varied diets for astronauts and to make space meals more appetising, scientists have been looking at ways of producing fresh food for astronauts in flight. In 2001, German researchers designed an artificial ecosystem to provide a continuous supply of fresh fish in a spacecraft.

But breeding live animals for food has drawbacks - they produce excrement, and killing them generates a lot of waste too. So NASA is paying for Benjaminson to go one step further and grow just the animals' edible muscle.

Initial experiments to see if the idea could work were rather grisly, the story continues. Benjaminson's group cut chunks of muscle five to 10 centimetres long from large goldfish. After washing the chunks in alcohol, they immersed them in a vat of foetal bovine serum, a nutrient-rich liquid extracted from the blood of unborn calves, which biologists usually use for growing cells in the lab.

After a week in the vat, the fish chunks had grown by 14 per cent, Benjaminson and his team found. To get some idea whether the new muscle tissue would make acceptable food, they washed it and then dipped it in olive oil flavoured with lemon, garlic and pepper. Then they fried it and showed it to colleagues from other departments.

"We wanted to make sure it'd pass for something you could buy in the supermarket," Benjaminson said. The results look promising, on the surface at least. "They said it looked like fish and smelled like fish, but they didn't go as far as tasting it," continued Benjaminson. They were not allowed to in any case - Benjamison will first have to get approval from the US Food and Drug Administration.

Benjaminson concedes that people might be reluctant to eat food grown in foetal bovine serum - not least because of worries about the transmission of vCJD through any rogue prion proteins it may contain.

He tried growing chunks of goldfish muscle in liquid mushroom extract instead, but although the tissue survived for a week, it did not grow. He is hoping to find a friendlier substitute for bovine serum before trying the technique on chicken, beef and lamb.

The idea has received a cautious welcome. "Fish mass grown in a nutrient broth sounds as unappealing as some of the other food astronauts take up with them, but these things have got to be explored," said Colin Pillinger, head of the Planetary Space Sciences Research Institute at the Open University in Milton Keynes. "I think it'd be more appropriate when you've got a base set up on a planet - the sort of equipment you need for biotechnology is fragile. Who knows what would happen to it during launch and the flight," he told the New Scientist.