VOA科学技术2024--Researchers: Bacteria Could Help Reduce 'Greenhouse' Gas

Very small organisms that live in the world's farm fields release nitrous oxide¹ gas.

Some scientists link the gas to climate change. They are looking for a way to deal with the issue.

Now, some researchers think they have found bacteria that can help reduce the amount of nitrous oxide released. In a recent publication of Nature, scientists said tests in the laboratory and in the field showed that one kind of bacteria reduced nitrous oxide without hurting other microbes in the soil. The bacteria also survived well in soil and would not be very costly² to produce.

Lars Bakken is with the Norwegian University of Life Sciences. He was one of the writers of the study. Bakken said, "It opens up...a number of new possibilities in bioengineering of the farmed soil."

The Associated Press reports that nitrous oxide can warm the atmosphere 265 times more than an equal amount of carbon dioxide. Nitrous oxide can remain in the atmosphere for more than a hundred years.

Farmers' use of nitrogen fertilizer drives up the amount of nitrous oxide produced in soil.

The U.S. Environmental Protection Agency said that, in 2022, nitrous oxide made up six percent of all U.S. greenhouse gas emissions³ from human activities.

That is a big problem in agriculture, said Lori Hoagland of Purdue University in the state of Indiana. Hoagland was not involved in the recent study.

She described the plan to reduce nitrous oxide as "really interesting."

How the work was done

Bakken and other researchers used organic waste to grow their bacteria. Building on past work, the researchers looked for a microorganism that would last long enough to reduce nitrous oxide emissions without staying in the soil so long that it hurt other life forms that are important for crop health.

In field tests, the researchers used robots to measure nitrous oxide emissions during the day and during the night.

They compared conditions in soil with and without the bacteria. Researchers found the bacteria reduced the nitrous oxide emissions of the first fertilizer treatment by 94 percent.

Two weeks later, the bacteria reduced the emissions of a second fertilizer treatment by about half. After about three months, there was no difference in the makeup⁴ of microbial life forms. This suggested to the researchers that their bacteria would not change or hurt the soil.

The bacteria that researchers used is found naturally in anaerobic⁵ digesters, machines that are already being used to turn organic waste products like cow manure⁶ into biofuels. The researchers said the bacteria are not genetically⁷ modified. That might ease acceptance of their use, said Paul Carini of the University of Arizona.

Carini was also not involved in the research.

Bakken said the bacteria could be included in some fertilizers on farms in three to four years if people think it is worth the cost.

Carini thinks using the bacteria is worth it.

"Any time you're using a waste product from one industry to benefit another industry, that's pretty cost effective," he said.

However, Bakken pointed⁸ out that farmers are not paid for reducing nitrous oxide emissions. He thinks there must be additional incentives¹⁰ for emissions reductions. "The task for the authorities is to install policy instruments that makes it profitable in one way or another," he said.

Hoagland, the Purdue professor, said more research in field conditions would likely be needed before the bacteria could be used worldwide. That is because soil is different in places around the world.

"If they can get this to work across soils...it would just have a tremendous impact, for sure," she said.

Words in This Story

fertilizer - n. a substance added to soil to increase crop production

modify - v. to change or alter

benefit - v. to help or have a positive effect on something

incentive⁹ - n. a reward that makes you want to do something

impact -n. a result from doing something

1 oxide   

n.氧化物

参考例句：

• Oxide is usually seen in our daily life.在我们的日常生活中氧化物很常见。
• How can you get rid of this oxide coating?你们该怎样除去这些氧化皮？

2 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

3 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

4 makeup   

n.组织；性格；化装品

参考例句：

• Those who failed the exam take a makeup exam.这次考试不及格的人必须参加补考。
• Do you think her beauty could makeup for her stupidity?你认为她的美丽能弥补她的愚蠢吗？

5 anaerobic   

adj.厌氧的

参考例句：

• Anaerobic respiration occurs only in particularly active tissues such as muscles during severe exercise. 厌氧呼吸只有在处于剧烈运动状态的肌肉等特别活跃的组织中才会发生。
• Infection,especially anaerobic infection, is much more apt to occur.感染，特别是厌氧感染很容易发生。

6 manure   

n.粪，肥，肥粒；vt.施肥

参考例句：

• The farmers were distributing manure over the field.农民们正在田间施肥。
• The farmers used manure to keep up the fertility of their land.农夫们用粪保持其土质的肥沃。

7 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

8 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

9 incentive   

n.刺激；动力；鼓励；诱因；动机

参考例句：

• Money is still a major incentive in most occupations.在许多职业中，钱仍是主要的鼓励因素。
• He hasn't much incentive to work hard.他没有努力工作的动机。

10 incentives   

激励某人做某事的事物( incentive的名词复数 )； 刺激； 诱因； 动机

参考例句：

• tax incentives to encourage savings 鼓励储蓄的税收措施
• Furthermore, subsidies provide incentives only for investments in equipment. 更有甚者，提供津贴仅是为鼓励增添设备的投资。 来自英汉非文学 - 环境法 - 环境法