新的人工光合作用过程可以在黑暗中种植植物

Scientists have developed an artificial photosynthesis process that can grow plants in the dark. The process is designed to provide a new way to produce food as worldwide demand grows.

Photosynthesis involves plants taking in energy from the sun to produce life-supporting carbon and oxygen. The process is important to support the growth of many plants.

But scientists have estimated that only about 1 percent of energy from the sun is actually captured by plants that produce food.

Researchers report in a new study that the artificial photosynthesis method they developed performed up to 18 times more efficiently in growing some foods. And the process can be carried out in complete darkness.

Results of the study recently appeared in the publication Nature Food. The research team included members from the University of California Riverside and the University of Delaware.

Researchers used an "electrolyzer system" to turn carbon dioxide, electricity and water into acetate. Acetate is the main compound found in many household products, including vinegar.

The electrolyzer process effectively turned 57 percent of carbon molecules in carbon dioxide into acetate, University of Delaware researchers said in a statement. The resulting acetate mixture was then used as food to grow plants in the dark.

The researchers experimented with nine different food plants. These included lettuce, rice, peas, tomatoes, pepper and tobacco. The team reported that all these plants were able to take in carbon from the acetate.

Experiments were also carried out with algae, yeast and a fungus that produces mushrooms. The study found that, for algae, the process was four times more efficient than growing the material photosynthetically with sunlight. And yeast production was 18 times more efficient than the usual process involving sugar collected from corn.

Lettuce produced the best results from artificial photosynthesis out of all the food crops tested.

"We were able to grow food-producing organisms without any contributions from biological photosynthesis," said the co-writer of the study, Elizabeth Hann. She is a doctoral candidate at UC Riverside's Jinkerson Lab.

Hann added that the process is much more efficient at turning energy into food than the biological photosynthesis methods, which have taken place for millions of years.

The researchers also reported that the process increased energy efficiency, too. When used together with a solar cell to power the electrolyzer, the method required just one-fourth the energy to grow the same amount of food created by sunlight and natural photosynthesis.

The scientists said their method could help fight the effects of climate change that are making traditional crop-growing more difficult.

"Drought, floods and reduced land availability would be less of a threat to global food security if crops for humans and animals grew in less resource-intensive, controlled environments," the researchers noted.

Robert Jinkerson is a professor of chemical and environmental engineering at UC Riverside. He said growing foods through artificial photosynthesis could help the world meet its rising demand for food without the expansion of agricultural lands.

"Using solar energy to power our process could allow for more food or animal feed to be produced on a given area of land," Jinkerson said.

The researchers said they plan to continue improving the electrolyzer system to produce a more effective acetate mixture. They also want to explore ways to possibly bioengineer plants that grow completely on acetate.

I'm Bryan Lynn.

Bryan Lynn wrote this story for VOA Learning English, based on reports from UC Riverside, the University of Delaware and Nature Food.

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artificial – adj. not natural, but made by people

efficient – adj. working well and not wasting time or energy

vinegar – n. a sour, acidic liquid that is often used in food preparation

fungus – n. a kind of plant without leaves that gets its food from other living or delaying things

contribution – n. something used to help produce or develop something or help make it successful

solar – adj. relating to or involving the sun

drought – n. a long period of time during which there is very little or no rain

allow – v. to permit