As scientists understand more about microbes, it seems that the miniscule life forms have the potential to contribute to a host of useful activities—making biofuels, fighting human disease, improving high tech, you name it!

Now, a feature article in the September issue of Scientific American looks at how soil microbes could revolutionize agriculture.

Soil microbes include everything from bacteria to fungi, and article author Richard Conniff likes to call the lot collectively “the agribiome.” These microscopic life forms have the potential to solve many crises facing agriculture today—everything from climate change and drought to Salmonella and other food-bourn illnesses, from the costs of man-made fertilizers to the GMO controversy.

Conniff’s article comes on the heels two other papers that highlight the importance of soil microbes. In a paper published last week in the Proceedings of the National Academy of Sciences, a team of British scientists emphasizes how important soil microbe diversity is for European crops. And two weeks ago, American researchers determined that soil microbes are responsible for controlling carbon in the soil—an important factor in retaining the important mineral in the dirt as temperatures rise and the climate warms.

The Scientific American article gives many examples of these crucial, unseen microbial workers. Bacteria found in soil on the United States West Coast can kill Salmonella, Conniff reports, so the USDA is looking at introducing the bacteria in East Coast soils to stop the occasionally deadly outbreaks.

And instead of genetically modifying actual crops to withstand drought conditions, Mexican scientists are looking at modifying bacteria to strengthen the plants in the soil at their roots.

Mycorrhizal fungi in the soil are heroes in both the SciAm article and the PNAS study. The fungi deliver much-needed phosphate to crops, an easier and cheaper way to get the important mineral to the plants to help them grow. Artificial fertilizers can be expensive, especially for farmers in developing countries, and harm the natural soil ecosystem. Run-off from these fertilizers also contaminates freshwater and marine environments. A simple animation of how the fungi works to help plants is available here.

(Mycorrhizal fungi also play a heroic role in the next Academy planetarium show! Currently in production and set for a fall 2014 opening date, the latest production from our visualization studio will highlight the complex relationships in ecosystems—and how humans fit into the picture.)

If farmers and scientists can acknowledge that collaborating with microbes can play a crucial role in farming, “we will have come a step closer to feeding a hungry world,” Conniff concludes.

The lead author of the PNAS paper, Franciska de Vries, says, “This research highlights the importance of soil organisms and demonstrates that there is a whole world beneath our feet, inhabited by small creatures that we can’t even see most of the time. By liberating nitrogen for plant growth and locking up carbon in the soil they play an important role in supporting life on Earth.”

Mycorrhizal fungi image: Nilsson et al. BMC Bioinformatics

The fungi control the ants with mind-altering chemicals, according to Wired Science:

Once infected by spores, the worker ants, normally dedicated to serving the colony, leave the nest, find a small shrub and start climbing. The fungi directs all ants to the same kind of leaf: about 25 centimeters above the ground and at a precise angle to the sun (though the favored angle varies between fungi).

Once the ant arrives at the right leaf, it dies and the fungus takes over. It can produce spores from a single dead ant for up to a year! Wired has some pretty gnarly pictures, if you feel the urge.

The researchers studied these fungi in the wild, not the lab (which has been the trend), and reported their findings last week in the open access, online journal, PLoS One.

In their paper, the authors draw attention to undiscovered, complex, biological interactions in threatened habitats. The four new species all come from the Atlantic Rainforest of Brazil, the most heavily degraded biodiversity hotspot on the planet with ninety-two percent of its original coverage gone. The fungi keep the ant population in check—a tip in the balance could wreak havoc on the ecosystem.

And fungi from this group contribute to both traditional and modern medicine. Again, from Wired:

Organ transplant patients, for example, receive ciclosporin—a drug that suppresses the immune system, reducing the chance the body will reject the new tissue. Chemicals from this same fungal group are also used for antibiotic, anti-malarial and anticancer drugs.

The researchers hope to understand more about this group of fungi before it’s too late. Ants may feel differently…

Image courtesy of PLoS One

A species’ survival often depends on how skillfully they can beat out another species for food or other resources. But sometimes, a species’ survival depends on how well they work with their neighbor. If each organism helps the other, they can both flourish. This process, called “symbiosis,” explains why bacteria thrive in our guts (because we thrive with them), how sharks don’t seem to mind the so-called “cleaner fish” that dart in and out of their mouths, and how delicate coral reefs can grow to the size of a small continent.

There are thousands of examples of symbiotic relationships on planet Earth. But has this practice always existed? In a study published last week, scientists uncovered evidence of a symbiotic relationship that existed over 470 million years ago. A relationship that paved the way for nearly every land organism on Earth.

In the November 2 issue of Nature Communications, a research team from the Royal Botanic Gardens and the University of Sydney pieced together earlier days of complex life by studying one of the most ancient land plants still in existence, the thalloid liverwort. Liverworts, often a nuisance in backyard gardens and greenhouses, have a small and flat ribbon-like structure.

Scientists have long suspected that the secret to the liverwort’s early success was a relationship with fungi living in the soil. But no one had been able to test it. Until now.

The team placed both liverwort and fungi in tightly controlled growth rooms to recreate Earth’s early days – hot and volatile. They found that when the fungi colonized the liverwort (a common fungal practice), the liverwort vastly improved its ability to take in carbon dioxide (CO₂). As a result, it grew and reproduced faster than if no fungi had been present. The fungi not only improved the liverwort’s ability to grow and reproduce, it helped the liverwort release substantial amounts of oxygen into the atmosphere. Something sorely lacking in Earth’s earliest days, and something for which we should all be thankful.

So what did the fungi get in return? They fed off the extra carbon the growing plants produced. In one experiment, the team found that just one liverwort plant could support fungi encompassing two tennis courts.

Professor David Beerling from the University of Sheffield, one of the authors of the study, was excited about how this research can help shed light on the earliest days of our planet. “By studying these ancient plants,” he says, “we open a window on the past to investigate how the earliest land plants evolved.”

Anne Holden, a docent at the California Academy of Sciences, is a PhD trained genetic anthropologist and science writer living in San Francisco.

Creative Commons image by Eric Guinther

Much exciting news came out of the conference, read on…

First up: Bacteria that make you smarter and calmer

On Monday, researchers announced that exposure to specific bacteria in the outside environment could increase learning behavior.

The bacteria are Mycobacterium vaccae, a natural soil bacterium that “people likely ingest or breath in when they spend time in nature,” says Dorothy Matthews, PhD of The Sage Colleges in Troy, New York, one of researchers on the project.

The researchers fed mice the live bacteria and assessed their ability to navigate a maze compared to control mice that were not fed the bacteria. “We found that mice that were fed live M. vaccae navigated the maze twice as fast and with less demonstrated anxiety behaviors as control mice,” says Matthews.

She continues, “It is interesting to speculate that creating learning environments in schools that include time in the outdoors where M. vaccae is present may decrease anxiety and improve the ability to learn new tasks.”

Next: Honey Bee Colony Collapse Disorder

Yesterday the news was not so good. Scientists from the US Department of Agriculture presented a study blaming a fungus and a family of viruses for the worldwide honeybee disappearance also known as Colony Collapse Disorder (CCD).

According to the BBC,

David Mendes, the president of the American Beekeeping Federation, says that biological pathogens are certainly involved – but that there might be something that affects the bees’ immune system in the first place that then allows these pathogens to infect them more easily.

Whichever came first, scientists are hoping that at least knowing the cause, they can start to help the much-needed bees. Good nutrition seems to help stop the fungus and some beekeepers are looking toward queen bees that are resistant to that family of viruses.

Au Currant Microbes: Bacteria Cleaning-up the Oil Spill

New Scientist described today that at the conference:

Jay Grimes of the University of Southern Mississippi in Hattiesburg reported that over the past few years, researchers have found that dozens of different kinds of marine bacteria have a healthy appetite for oil.

He said that water samples from the Gulf of Mexico are showing signs that marine bacteria are already pitching in to help with clean-up efforts, and that populations of these bacteria in this area are likely to boom as they feast on the oil from the Deepwater Horizon disaster.

The bacteria better be careful, however, because the dispersants added to breakdown the oil maybe harmful to the microbes. A team of scientists funded by NSF is headed to the Gulf to find out:

The team seeks to understand how the dispersants added to the spill will interact with natural compounds produced by microbes, and how this will impact the ability of different microbes to break down the oil.

For Bonus Points: Bacteria that causes rain and snow.

And finally, The New York Times published a great story earlier this week about bacteria that may be involved with precipitation in the atmosphere—essentially, rain and snow. It’s been studied for over 30 years, but new tools and technology are providing clearer pictures, making it an exciting field of microbiology research.