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Aug. 22, 2013

Quest for the missing bacteria

A Michigan State University scientist will use a $1.9 million grant from the National Science Foundation and the Biotechnology and Biological Sciences Research Council (United Kingdom) to solve the mystery of the missing bacteria.

The bacteria, discovered in a German charcoal pit in the 1990s, is a unique organism that could hold the key that enables plants to grow without the aid of nitrogen added through manmade fertilizers.

Nitrogen is essential for all living organisms. Although nitrogen gas makes up 78 percent of the atmosphere, this form is unusable to plants and animals. Many bacteria can perform nitrogen fixation – the ability to fix atmospheric nitrogen into ammonia, a compound used in critical biological functions.

However, many crops don’t interact with these beneficial bacteria. They obtain their nitrogen fix through chemical fertilizers.

Most nitrogen-fixing bacteria use an enzyme that does not work when oxygen is present, but the heat and toxic gas-loving strain appeared to have exceptional properties. Studies on this bacterium stopped around 20 years ago. When the studies ceased, the novel organism was lost, said Maren Friesen, MSU plant biologist.

“Rediscovering this bacterium, or ones with similar properties, would be a game-changer,” she said. “It contains an unusual system for fixing nitrogen in the presence of oxygen, which could be a missing piece in the puzzle for creating nitrogen-fixing plants.”

Producing artificial fertilizers is costly and uses vast amounts of fossil fuel. It also generates environmental problems, such as increased greenhouse gas emissions and fertilizer runoff into rivers. A plant that can fix its own nitrogen would require less fertilizer, diminishing the use of fossil fuels and environmental harm.

Finding the lost bacteria will see Friesen’s team scouring the fiery corners of the globe, searching Hawaiian volcanoes, American coal seam fires and German fire pits for the elusive bacteria, in a bid to recover its lost potential.

Friesen will collaborate with researchers from Imperial College London in the hope of finding the original bacterial strain, as well as new oxygen-tolerant, nitrogen-fixing strains, in these seemingly inhospitable environments. The team will then study the genetics and biochemistry of these strains with an eye toward transferring oxygen-tolerant nitrogenase enzymes – found in the bacteria – into plants.

Friesen’s research was one of four NSF grants announced today, totaling $8.9 million to fund three teams of U.S. and United Kingdom scientists to revolutionize farming by giving crops the ability to thrive without using costly and polluting chemical fertilizers.

By: Layne Cameron