Preparing for a thaw: How Arctic microbes respond to a warming world

[OKIsItJustMe]

http://www.eurekalert.org/pub_releases/2011-11/dgi-pfa102811.php

Public release date: 6-Nov-2011

Contact: David Gilbert
[e-mail]
http://www.jgi.doe.gov/">DOE/Joint Genome Institute

Preparing for a thaw: How Arctic microbes respond to a warming world

WALNUT CREEK/BERKELEY, Calif.—From the North Pole to the Arctic Ocean, the frozen soils within this region keep an estimated 1,672 billion metric tons of carbon out of the Earth's atmosphere. This sequestered carbon is more than 250 times the amount of greenhouse gas emissions attributed to the United States in the year 2009. As global temperatures slowly rise, however, so too do concerns regarding the potential impacts upon the carbon cycle when the permafrost thaws and releases the carbon that has been trapped for eons. Like so many of the planet's critical environmental processes, the smallest players—microbes—have the most significant influence over the eventual outcome.

To answer this question, researchers from the U.S. Department of Energy (DOE) Joint Genome Institute (JGI), the Earth Sciences Division (ESD) within Berkeley Lab, and the U.S. Geological Survey collaborated to understand how the microbes found in permafrost respond to their warming environment. Among the findings, published online November 6 in the journal Nature, is the draft genome of a novel microbe that produces methane, a far more potent greenhouse gas than carbon dioxide. This microbe, not yet named, lives in the permafrost, and was assembled out of the collection of genomes—the metagenome—isolated from the frigid soil. The assembly challenge is similar to building one complete jigsaw puzzle from a large collection of pieces from many different puzzles.

"The permafrost is poised to become a major source of greenhouse gases as the temperature in the Arctic is expected to increase dramatically compared to the expected temperature increase in many other regions of the world," said ESD's Janet Jansson, corresponding author and initiator of the study (first supported by a grant to her from DOE Laboratory Directed Research and Development funds). "By applying metagenomics to study microbial community composition and function, we can help to answer questions about how the currently uncultivated and unstudied microbial species residing in permafrost cycle organic carbon and release greenhouse gases during thaw," Jansson said. "This will provide valuable information that could lead to improved carbon cycle models and eventual mitigation strategies."

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Waldrop cored meter-deep permafrost samples from a peaty black spruce forest along Hess Creek, Alaska. Each sample was then divided to distinguish between the seasonally thawed "active" layer, which comprised the top third of the core, and the permanently frozen "permafrost" horizon underneath. The samples were incubated during thaw at 5°C and then sent to the Jansson lab for DNA extraction and analyses At the DOE JGI, the team led by Director Eddy Rubin and his postdoctoral fellow Rachel Mackelprang, (now at California State University-Northridge) sequenced microbial DNA from the samples. "These microbial communities are extremely diverse," said Mackelprang. "A single gram of soil may contain thousands of different bacterial species and billions of cells. Additionally, most of these microbes cannot be grown in the laboratory, making this an extremely difficult area to study." The data were then analyzed in collaboration with Jansson and her team at ESD, including Kristen DeAngelis, Maude David, and Krystle Chavarria.

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http://dx.doi.org/10.1038/nature10576

[Dragonbreathp9d]

1. Never considered this aspect-

Could there be microbes frozen ( soon to be melted) that could potentially be detrimental once reintroduced?

[eppur_se_muova]

2. Hmmm ... there were graves of 1918 flu victims on Svalbard and in Alaska ...

they've isolated DNA (or is it RNA?) from them to study the virus.

Now I guess they'll just thaw and spread the love.

[sarge43]

3. Or smallpox victims. Has to be some of them too. n/t