雅思阅读 37: Meat Without the Animal（不来自动物的肉）

改编自 Foods (PMC) 综述 / industry reports（2026年）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://pmc.ncbi.nlm.nih.gov/articles/PMC12469421/

Reading Passage

A. The case for producing meat without slaughtering an animal has, for years, been easy to state and hard to realise. Livestock occupies a vast share of the world's land and fresh water, contributes a notable slice of global greenhouse-gas emissions — cows in particular burp methane, a far more potent warming gas than carbon dioxide — and raises serious ethical questions about how the animals themselves are kept in crowded conditions. Cultivated meat promises to sidestep all of that. Instead of rearing a whole animal for months or years, most of whose body is not eaten, the idea is to take a small sample of muscle and fat cells, then multiply those cells in large stainless-steel vessels called bioreactors until there is enough to form a cut of meat. It is, on paper, a cleaner, more controllable and more land-efficient way of doing something humanity has always done by butchery. The problem has always been cost, and for a long time it looked as though the product would remain a curiosity for wealthy tastings rather than a supermarket staple.

B. The process begins with a harmless biopsy taken from a living animal — a small sample of tissue, from which cells can be cultured indefinitely. The cells recovered are not fully grown muscle fibres but stem-like progenitors, capable of dividing many times before they specialise. Immersed in a warm, oxygenated fluid that feeds them glucose, salts and growth factors, they multiply by the billion, doubling in number every day or two; to turn a loose slush of cells into something with the familiar grain of meat, they are grown on or within a scaffold — a temporary, edible structure, often a plant-derived gel, that encourages the cells to organise themselves into aligned fibres and to lay down fat between them, as real muscle does. Without such support the result is a fine mince or patty, not a steak, which is why the earliest approved products were chicken nuggets and formed pieces rather than the marbled cuts that consumers recognise as premium. The whole system is, in effect, a factory for rebuilding muscle tissue outside the body of the cow, chicken or fish it came from, and one that can, in principle, produce pork without a pig or beef without a cow.

C. For two decades, one ingredient strangled the economics. The standard fluid used to feed animal cells in the laboratory is fetal bovine serum, a blood-derived extract drained from unborn calves at slaughter, which laboratory science adopted in the mid-twentieth century because no-one fully understood, let alone could reproduce, the cocktail of hormones and nutrients it contains. It is remarkably effective at sustaining cells, but it is expensive, variable from batch to batch — a headache for any manufacturer needing a consistent product — ethically troubling, and inescapably tied to the very animal industry the technology aims to replace. Worse, the nutrient broth in which cells grow can account for more than half — and, in early estimates, as much as 95 per cent — of the entire cost of production, far outstripping the cost of the vessels or the labour. As long as every kilogram of meat demanded litres of serum, no laboratory-grown product could compete on price with meat from a farm, and the founders of the industry struggled to explain when, if ever, their steaks would be affordable enough to escape the tasting-menu circuit.

D. That bottleneck has begun to loosen. Researchers have formulated serum-free recipes, replacing the serum with plant-derived protein digests and precisely manufactured growth factors produced by microbes in fermentation tanks rather than extracted from animals. Pilot plants report that such media can now be produced for only a few cents a litre, a dramatic fall from the prices of a decade ago, and a parallel push to engineer cells that divide indefinitely — using gene editing to remove a gene that normally limits how often a cell may replicate, the biological equivalent of giving them an inexhaustible lifespan — means a single biopsy need never be repeated. Coupled with much larger bioreactors, some reaching hundreds of thousands of litres, these advances have reportedly cut overall production costs by roughly three-quarters. The remaining obstacles are less dramatic but real: preventing bacterial contamination in enormous, nutrient-rich vessels that microbes would colonise in hours, and supplying enough of the still-pricey recombinant growth factors at the volumes a commercial plant would demand.

E. Commercial viability, however, depends on more than a falling price tag. Approval has arrived unevenly across the world. Singapore cleared cultivated chicken for sale first, in 2020, and still serves it in a small number of restaurants; the United States followed in 2023 under a joint regime shared between its drug regulator and its food-safety service, and Israel authorised sales the next year. The European Union, by contrast, has been slower, its novel-food approvals taking eighteen months or more, and large markets elsewhere still await clear guidance on what may be sold and how it must be labelled. Consumer acceptance is patchy too: surveys show that many shoppers are curious but uneasy about food grown in a vessel rather than on a farm, and some object on principle to the very idea, however clean the process. Cultivated meat is therefore not about to replace the abattoir tomorrow, and sceptics reasonably point out that plant-based imitations already do much of the job far more cheaply, without the need for stainless-steel vessels at all. Yet the combination of a de-fettered cell line, a cheap animal-free feedstock and a growing list of approving governments suggests that the product has at least escaped the laboratory and entered the uncomfortable but real world of regulation, prices and supermarket shelves.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. The laboratory process, from biopsy to scaffold ii. Why one traditional ingredient destroyed the economics iii. The technical breakthroughs that are cutting the cost iv. How the abattoir industry is fighting back v. Why approval and acceptance still lag behind the science vi. The environmental damage caused by bioreactors vii. The history of butchery in ancient Rome

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. What is the role of the scaffold in cultivated meat? A. It sterilises the bioreactor. B. It helps cells organise into fibres and fat, giving texture. C. It supplies oxygen to the cells. D. It cools the nutrient broth.

6. Why was fetal bovine serum such a problem? A. It was cheap but unsafe. B. It was expensive, inconsistent and ethically unacceptable. C. It tasted strongly of blood. D. It killed all animal cells.

7. How have engineers reduced dependence on serum? A. By feeding cells on raw meat. B. By using plant-derived digests and microbe-made growth factors. C. By freezing the cells solid. D. By raising calves in laboratory conditions.

8. Which country approved cultivated chicken for sale first? A. The United States. B. Israel. C. Singapore. D. Germany.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. The nutrient fluid can account for more than half of production costs.
10. Serum-free media still contain blood from unborn calves.
11. Larger bioreactors have helped to lower production costs.
12. The European Union approved cultivated meat in 2020.
13. Most consumers say they will refuse to eat cultivated meat.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

Cells are first taken from a living animal by means of a small (14) __________. In the early years they were fed on fetal bovine serum, an extract drawn from unborn (15) __________.

答案与解析

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