It may soon be possible to engineer plants that can develop their own fertilizer by using atmospheric nitrogen to create chlorophyll for photosynthesis, according to a team of Indian-origin researchers in the U.S. If farmers are given the opportunity to use the bacteria for their benefit, the plants will be able to utilize the nitrogen present in the air and the annual expenditure on chemical fertilizers will be reduced substantially!
The researchers from Washington University in St. Louis engineered a bacteria that uses photosynthesis to create oxygen during the day, and at night, uses nitrogen to create chlorophyll for photosynthesis.
The research, published in the journal mBio, could eliminate the use of some human-made fertilizer, which has a high environmental cost.
This discovery could have a revolutionary effect on agriculture and the health of the planet, according to scientists Himadri Pakrasi and Maitrayee Bhattacharyya.
Washington University research team led by Himadri Pakrasi and Maitrayee Bhattacharyya-Pakrasi, has come up with a way to increase the overall food production by farmers. A new bacterium has been created than can make its own fertilizer out of thin air!
Pakrasi, the Glassberg-Greensfelder Distinguished University Professor in the Department of Biology in Arts & Sciences and Director of the International Center for Energy, Environment and Sustainability (InCEES), with the help of his team, created the bacteria called Cyanothece, which can make fertilizer using the nitrogen in the atmosphere.
The earth's atmosphere contains around 78 percent nitrogen and this team of researchers wanted to engineer a bacterium which can fix this nitrogen to some extent.
This bacterium can help them into engineering plants which can do the same.
Apart from its nitrogen-fixing properties -- which can also be found in Cyanobacteria -- these new bacteria has a circadian rhythm.
This means that they follow the human sleep cycle and fix nitrogen only at night, after converting sunlight to chemical energy during the day.
Fertilizers usually act with a lot of energy while producing an abundance of greenhouse gas.
They usually release nitrogen which is taken up by plants during photosynthesis but studies show that only 40 per cent of the produced nitrogen is used up by plants.
Another problem is the pollution of water bodies when these fertilizers are washed off.
This can kill-off a lot of organisms in the water.
The research team had plans of taking the genes from this new bacterium and incorporating them in another type of cyanobacteria called Synechocystis so that the nitrogen in the air can be fixed.
To capture a circadian rhythm in the bacteria, the researchers added the genes of cyanothene in Synechocystis after manually removing the oxygen from the latter.
After some tweaking, the scientists observed that nitrogen was being fixed 30 per cent faster than the normal rate.
Washington University’s Pakrasi lab based its research on the fact that, although there are no plants that can fix nitrogen from the air, there is a subset of cyanobacteria that is able to do so.
The bacteria used in this research, Cyanothece, is able to fix nitrogen because it has a circadian rhythm.
Cyanothece photosynthesise during the day, converting sunlight to the chemical energy they use as fuel, and fix nitrogen at night, after removing most of the oxygen created during photosynthesis through respiration, researchers said.
The research team took the genes from Cyanothece, responsible for this day-night mechanism, and put them into another type of cyanobacteria, Synechocystis, to coax it into fixing nitrogen from the air too.
The next steps for the team are to dig deeper into the details of the process, perhaps narrow down even further the subset of genes necessary for nitrogen fixation.
The team will then collaborate with other plant scientists to apply the lessons learned from this study to the next level: developing nitrogen-fixing plants.
