A meaty questionNO.3
IF YOU have ever longed for a meat substitute that smelt and tasted like the real thing, but did not involve killing an animal, then your order could be ready soon. Researchers believe it will soon be possible to grow cultured meat in quantities large enough to offer the meat industry an alternative source of supply.
Growing muscle cells (the main component of meat) in a nutrient broth is easy. The difficulty is persuading those cells to form something that resembles real meat. Paul Kosnik, the head of engineering at a firm called Tissue Genesis, is hoping to do it by stretching the cells with mechanical anchors. This encourages them to form small bundles surrounded by connective tissue, an arrangement similar to real muscle.
Robert Dennis, a biomedical engineer at the University of North Carolina, believes the secret of growing healthy muscle tissue in a laboratory is to understand how it interacts with its surroundings. In nature, tissues exist as elements in a larger system and they depend on other tissues for their survival. Without appropriate stimuli from their neighbours they degenerate. Dr Dennis and his team have been working on these neighbourly interactions for the past three years and report some success in engineering two of the most important-those between muscles and tendons, and muscles and nerves.
At the Touro College School of Health Sciences in New York, Morris Benjaminson and his team are working on removing living tissue from fish, and then growing it in culture. This approach has the advantage that the tissue has a functioning system of blood vessels to deliver nutrients, so it should be possible to grow tissue cultures more than a millimetre thick-the current limit.
Henk Haagsman, a meat scientist at the University of Utrecht in the Netherlands, is trying to make minced pork from cultured stem cells with the backing of Stegeman, a sausage company. It could be used in sausages, burgers and sauces.
But why would anyone want to eat cultured meat, rather than something freshly slaughtered and just off the bone? One answer, to mix metaphors, is that it would allow vegetarians to have their meatloaf and eat it too. But the sausagemeat project suggests another reason: hygiene. As Ingrid Newkirk of PETA, an animalrights group, puts it, "no one who considers what’s in a meat hot dog could genuinely express any revulsion at eating a clean cloned meat product."
Cultured meat could be grown in sterile conditions, avoiding Salmonella, E. coli, Campylobacter and other nasties. It could also be made healthier by adjusting its composition-introducing heartfriendly omega-3 fatty acids, for example. You could even take a cell from an endangered animal and, without threatening its extinction, make meat from it. Giantpanda steak, anyone?
substitute
n.代用品，代替品；v.（for）代替，替换
［真题例句］ In talking to some scientists, particularly younger ones, you might gather the impression that they find the "scientific method" a substitute (n.) for imaginative thought.［1999年阅读5］
［例句精译］ 在和一些科学家，特别是年轻科学家交谈时，你可能会有这样一种印象：他们认为"科学方法"可以代替创造性思维。
resemble
v.像，类似
tissue
n.①织物，薄绢，纸巾；②（动、植物的）组织 |
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