Researcher uses grant to study little-known but largely useful microbes (7/21/2008)

Microbiology graduate students Kara DeLeon, left, and Kristen Brileya prepare soil samples in Matthew Fields' laboratory for transport to a research site. (MSU Photo by Kelly Gorham)

Montana State University microbiologist Matthew Fields spends his days trying to understand how interactions on a microscopic scale could change how we think of energy production, climate change and even soil contamination.

Fields studies the physiology and behavior of microbes - the tiny organisms that have inhabited virtually every square inch of the earth's surface for the past 3.5 billion years.

"Microbes have global impacts," Fields said. "They can grow fast and in large numbers, and there is always power in numbers."

Fields is particularly interested in how that power can be harnessed for human use. Last year, he received a five-year $1.65 million grant from the Department of Energy to study how microbes living together interact.

The grant is part of the Virtual Institute for Microbial Stress and Survival, a project led by the Lawrence Berkeley National Laboratory. Fields' work involves researchers at MSU and five other universities across the country, as well as scientists at three national laboratories.

Fields, who works at MSU's Center for Biofilm Engineering, said people are generally only aware of the microbes that make humans sick, such as E. coli. But those notorious species represent only a drop in earth's microbial ocean.

"Life on this planet is microbial," he said. "There is a vast amount going on in the microbial world that we don't understand. Microbes play significant roles in the carbon cycle, the nitrogen cycle, the phosphorous cycle, and we don't fully understand how."

Part of the reason microbes remain mysterious is the way they have traditionally been studied in the lab, Fields said. Researchers usually grow cultures of single microbe species and then explore how those monocultures react to different stimuli.

An image of Desulfovibrio vulgaris, one of the micrboes Fields studies. (Image courtesy of Melinda E. Clark)

"But monocultures in the lab are not like the real world," Fields said. "Seldom do organisms grow on their own in a real ecosystem."

Instead, Fields looks at the complex systems and communities microbes form naturally. The goal, he said, is not necessarily to understand which single variable produces a certain reaction. Rather, the goal is to understand the key mechanisms that drive the entire system.

Fields uses this system-based approach to study how the microbial communities living at sites contaminated by toxic heavy metals, such as uranium and chromium, may help stop the spread of those contaminants.

Some forms of those heavy metals are soluble in water, allowing them to seep into groundwater and spread beyond the contaminated site.

But Fields explained that some of the microbes he studies can, just by going through their natural life processes, make those metals insoluble. Instead of spreading, the metals are deposited in solid form at the contamination site.

"We're not getting rid of it, but we are treating and containing it so that it doesn't make people sick," Fields said.

Right now, a number of complications make this process hard to understand in real world terms, Fields said. Chief among those complications is the fact that microbes behave differently in biofilms - the complex, multi-species communities they tend to form in the real world - than they do when isolated. This means that any remediation solution involving microbes would have to be studied carefully and tailored to suit a specific site.

But Fields believes that, despite the complexity, microbial solutions will be cheaper and more efficient than traditional methods for remediating sites, which include chemically treating and physically removing the contaminated soil.

Fields hopes that this research will go a long ways toward showing people that microbes have much to offer.

"This is a microbial world," Fields said. "They're the most evolved creatures on the planet, and we have a lot to learn about them."

Note: This story has been adapted from a news release issued by Montana State University

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