Algae may hold the key to feeding the world’s burgeoning population. Don’t worry; no one is going to make you eat them. But because they are more efficient than most plants at taking in carbon dioxide from the air, algae could transform agriculture.
If their efficiency could be transferred to crops, we could grow more food in less time using less water and less nitrogen fertilizer.
New work from a team led by Carnegie’s Martin Jonikas published in Proceedings of the National Academy of Sciences reveals a protein that is necessary for green algae to achieve such remarkable efficiency. The discovery of this protein is an important first step in harnessing the power of green algae for agriculture.
It all starts with the world’s most abundant enzyme, Rubisco.
Rubisco “fixes” (or converts) atmospheric carbon dioxide into carbon-based sugars, such as glucose and sucrose, in all photosynthetic organisms on the planet. This reaction is central to life on Earth as we know it, because nearly all the carbon that makes up living organisms was at some point “fixed” from the atmosphere by this enzyme. The rate of this reaction limits the growth rate of many of our crops, and many scientists think that accelerating this reaction would increase crop yield
The funny thing about Rubisco is that it first evolved in bacteria about 3 billion years ago, a time when the Earth’s atmosphere had more abundant carbon dioxide compared to today. As photosynthetic bacteria became more and more populous on ancient Earth, they changed our atmosphere’s composition.
“Rubisco functioned very efficiently in the ancient Earth’s carbon dioxide-rich environment,” Jonikas said. “But it eventually sucked most of the CO2 out of the atmosphere, to the point where CO2 is a trace gas today.”
Learn more: How Algae Could Save Plants from Themselves