Miraculous Microbes!

What makes microbes so fascinating? The scientists who study them certainly do their best to make the microbeasties interesting! Passionate about the bacteria and archaea we can’t see, these researchers help us recognize the important role microscopic life plays on our planet.

At a fun- and prop-filled press conference at last week’s AAAS meeting, microbiologists spoke about one of the most ambitious, ongoing scientific projects—the Earth Microbiome Project (EMP).

The presentation began with grad students from Argonne National Laboratory at the University of Illinois handing out test tubes and swabs to reporters. Jack Gilbert wanted us to swab the front and back of our cell phones and the bottom of our shoes. His team will study the various microbiomes sampled and post results on Facebook later this week.

Janet Jansson of Lawrence Berkeley Lab then gave us the numbers. “In 1500, Leonardo DaVinci said that we know more about celestial bodies over our heads than the soil under our feet. And that’s still true.” Then she held up her prop, a cup of soil gathered at a nearby Vancouver park. “In this cup of soil, there are more microorganisms than stars in the Universe. In one teaspoon, there are over a billion microorganisms, and while we don’t know their identities or functions, many are responsible for the carbon and nitrogen cycling in the soil.”

There are far too many microorganisms, both in populations and “species” numbers, to sequence every one, so the EMP focuses on the broader microbiome. The project aims to understand “Earth's dark matter,” comparing microbiomes from one area to another. Whether soil, Antarctic ice, oceans, human hosts or insects, the EMP is trying to standardize the way we look at these microbiomes.

“Why should we care about the microbial world?” asked Rob Knight of the University of Colorado at Boulder, knowing the answer. But perhaps Gilbert answered it best. “This is a microbial world. They’ve been around for 3.8 billion years. They live on us and in us, making their living. Without them, we’d be dead. Without us, they would find something else.”

In fact, inside each of us, we humans have 100 trillion microbial cells, many more than cells than contain our actual genome.

In such a vast project, the EMP has only yet scratched the surface. They’ve created an overall map of which microbes live where and which habitats remain undersampled. The project isn’t just sampling the natural environment, but the built environment as well. One part of the project has folks taking samples from their hands, feet, and nasal passages—as well as their kitchen cabinets, bathroom doorknobs, and other residential surfaces, always asking what lives where and in what quantities.

The project is creating a baseline that could influence conservation efforts, Gilbert proposed. “If we take microbes endemic to threatened habitats, how can we use them to protect and rebuild those habitats? We may be able to restore environments, especially in the ocean. Or impacted communities like oil spills or the thawing permafrost.”

Miraculous microbes!