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"Air Feeders" -- The Discovery Files

The Discovery Files
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To enable plants to take advantage of Earth's nitrogen-rich atmosphere -- and reduce the need for fertilizer -- scientists have genetically engineered bacteria that can make use of nitrogen gas, a process called nitrogen fixation. If scientists can apply this engineering method -- in which nitrogen-fixing genes are inserted into a specimen that normally doesn't fix nitrogen -- to plants, it could change the face of agriculture, making more food available in less time with fewer environmental costs.

Credit: NSF/Karson Productions

Audio Transcript:

Something in the air.

I'm Bob Karson with the Discovery Files, from the National Science Foundation.

(Sound effect: farm field, tractor) When farmers fertilize crops, they're using the fertilizer as a delivery vehicle for nitrogen. What's weird is that the air around us is 78 percent nitrogen.

Why can't we find a way to get plants to simply pull the nitrogen they need right from the air? It'd be huge. No fertilizer equals no runoff, less environmental impact, lower cost, more people fed... and less... (Sound effect: cow moos) "fumes."

Scientists at Washington University in St. Louis have just shown the scenario is bacteria. They've engineered a bacterium that can make use of nitrogen sucked out of thin air -- a major step toward engineering plants that can do the same. It works partly because the kind of bacteria the team used have a circadian rhythm just like humans do. By day, they use photosynthesis to make their food. (Sound effect: crickets) By night, they use nitrogen to make chlorophyll they need for photosynthesis.

(Sound effect: switch on) The team has figured out which genes control that day-night mechanism. (Sound effect: switch off) Next steps: dig deeper into the details of the process, and work with other plant scientists toward getting plants to use nitrogen from the air to create their own fertilizer, too. They say the effects on agriculture and the health of the planet could be revolutionary.

In so many ways, this is a real... (Sound effect: light breeze) breath of fresh air.

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