Why do scientists chase unicorns?

February 1, 2016 by Layne Cameron

Scientists chase unicorns because if they could prove the existence of the magical beasts, the world would be a better place. Take Maren Friesen, Michigan State University plant biologist, for example. Her quest was to find near-mythical bacteria that could fix their own nitrogen. Her search for such magical beasties was based on results from Germany published in the 1990s that seemed to confirm their existence.

The end result, published in the current issue of Nature's Scientific Reports, proved that the elusive bacteria, Streptomyces thermoautotrophicus, did in fact exist but didn't have any mythical qualities.

Most nitrogen-fixing bacteria use an enzyme that does not work when oxygen is present. The heat and toxic gas-loving strain that Friesen studied appeared to have exceptional properties, including harboring a special enzyme that was insensitive to oxygen. So why go on such a quest?

"If they actually existed, it would mean we could have plants that could fix their own nitrogen, a compound used in critical biological functions, with no need for nitrogen fertilizers," said Friesen. "In this dream world, there would be less pollution, less nitrogen runoff into rivers and streams, less , less fuel being used to transport and apply fertilizer."

That is a unicorn worth chasing, she added.

So why is it worth proving that it's a myth, that it doesn't exist?

While Friesen and an international team of scientists remained highly skeptical of the bacteria's existence, the positive result in the literature had long tantalized researchers. However, there were no other papers from independent labs to confirm the original findings.

"This outlying result was always there, always lingering in published papers," Friesen said. "Now we've been able to bury this once and for all."

The myth began in Germany, where the bacteria were discovered, and their mythical properties were suggested. They thrived in the hot, toxic fumes over traditional charcoal fires where large quantities of wood were buried and burnt down.

Friesen's collaborators traveled to Germany and gathered samples while she went to Centralia, Pa., where underground coal fires have been burning for decades. She was somewhat surprised that she was able to find the bacteria, lending a bit of credence to the myth.

The tale grew even more when they produced a positive result in the laboratory, demonstrating that the bacteria did indeed fix their own nitrogen. This, however, turned out to be a tainted result.

"We learned that the gas that everyone had been using for the experiments was contaminated," Friesen said. "For the next experiments, we had to introduce a number of new controls, which included washing or purifying the gas we used."

Dispelling the myth turned out to be a roller coaster of results and reactions - from actually finding the missing to a positive result that bolstered the tall tale, and from conducting many, many more experiments to finally killing the bacterial unicorn.

While one mythical notion died, the concept of international collaboration and open data grew. Scientists from Harvard University, Imperial College (London), Aachen University (Germany) and Universidad Nacional de Rosario, Zavalla (Argentina) contributed to key aspects of the research. Rather than focus on one experiment, the team conducted many experiments around the world.

"By sharing data, you can have a lot of influence," Friesen said. "The most-influential datasets are the ones that everyone is using. And as this research demonstrated, it's better to compare your results to other researcher's data than believe a singular result. Reproducibility is really key to good science."

Even if it means a few unicorns must die.

Explore further: How plants interact with beneficial microbes in the soil

More information: Drew MacKellar et al. Streptomyces thermoautotrophicus does not fix nitrogen, Scientific Reports (2016). DOI: 10.1038/srep20086

Related Stories

How plants interact with beneficial microbes in the soil

January 12, 2016

Scientists have wondered for years how legumes such as soybeans, whose roots host nitrogen-fixing bacteria that produce essential plant nutrients out of thin air, are able to recognize these bacteria as both friendly and ...

Study: It's not cheating unless a species gets hurt

September 21, 2015

A review of dozens of key ecological studies has found very little evidence to support one of the field's commonly held beliefs: Cheating is widespread among 'mutualists,' species that cooperate with one another for mutual ...

Team studies diversity among nitrogen-fixing plants

June 16, 2015

Researchers at Chapman University and Columbia University have published a study in Nature Plants this month, called "Diversity of nitrogen fixation strategies in Mediterranean legumes." The recently published research focuses ...

Scientists find new research models to study food crops

July 10, 2015

Farmers often are required to apply nitrogen fertilizers to their crops to maintain quality and improve yields. Worldwide, farmers used more than 100 million tons of nitrogen in 2011, according to the United Nations Food ...

Recommended for you

Study shows how giraffe assassin bugs outwit spider prey

October 26, 2016

(Phys.org)—A biologist at Macquarie University in Australia has discovered the secret behind the giraffe assassin's ability to catch and kill spiders in their webs. In his paper published on the open access site Royal Society ...

New analysis of big data sheds light on cell functions

October 26, 2016

Researchers have developed a new way of obtaining useful information from big data in biology to better understand—and predict—what goes on inside a cell. Using genome-scale models, researchers were able to integrate ...


Adjust slider to filter visible comments by rank

Display comments: newest first

3.7 / 5 (3) Feb 01, 2016
The title is misleading. And the article is confusing, with changing subjects.

5 / 5 (1) Feb 01, 2016
Azotobacter is a genus of usually motile, oval or spherical bacteria that form thick-walled cysts and may produce large quantities of capsular slime. They are aerobic, free-living soil microbes which play an important role in the nitrogen cycle in nature, binding atmospheric nitrogen, which is inaccessible to plants, and releasing it in the form of ammonium ions into the soil (nitrogen fixation). In addition to being a model organism for studying diazotrophs, it is used by humans for the production of biofertilizers, food additives, and some biopolymers. The first representative of the genus, Azotobacter chroococcum, was discovered and described in 1901 by the Dutch microbiologist and botanist Martinus Beijerinck. Azotobacter species are Gram-negative bacteria found in neutral and alkaline soils, in water, and in association with some plants. Nitrogen fixation occurs naturally in the soil with the help of some types of bacteria and plants (for example, Azotobacter and legumes).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.