. 24/7 Space News .
CARBON WORLDS
Shunned by microbes, organic carbon can resist breakdown in underground environments
by Staff Writers
Stanford CA (SPX) May 02, 2017


A new study uncovered a previously unknown mechanism that explains why microbes sometimes fail to break down buried plant and animal matter. Above, the field site in the floodplains in the upper Colorado River Basin where soil samples were taken.

The soils and sediments beneath our feet can contain an astonishing amount of carbon - more than in all of the world's plants and the atmosphere combined - and represents a significant potential source of the greenhouse gas carbon dioxide.

In a new study, Stanford scientists have uncovered a previously unknown mechanism that explains why microbes sometimes fail to break down all the plant and animal matter, leaving carbon underfoot. Understanding where, and how long, this buried organic matter lingers is crucial for scientists and policymakers to better predict and respond to climate change.

"Our picture of how organic matter is broken down in soils and sediments is incomplete," said study lead author Kristin Boye, an associate staff scientist at the Stanford Synchrotron Radiation Lightsource at the SLAC National Accelerator Laboratory and former postdoctoral scholar at Stanford's School of Earth, Energy and Environmental Sciences. "With this study, we are gaining new insights into the mechanisms of carbon preservation in low- or no-oxygen subterranean environments."

In oxygen-starved places such as marshes and in floodplains, microorganisms do not equally break down all of the available organic matter, the study shows. Instead, carbon compounds that do not provide enough energy to be worthwhile for microorganisms to degrade end up accumulating. This passed-over carbon, however, does not necessarily stay locked away below ground in the long run. Being water soluble, the carbon can seep into nearby oxygen-rich waterways, where microbes readily consume it.

To date, models of local ecosystems and broader climate change have failed to take into account this newfound carbon preservation mechanism, having focused chiefly on microbial enzymes and the availability of other elements for organic matter breakdown.

"Soils and sediments are a huge and dynamic reservoir of carbon," said study senior author Scott Fendorf, a professor of soil biogeochemistry at Stanford Earth. "That's why we worry about turnover times here with regard to how fast organic carbon is degraded and released as carbon dioxide into the atmosphere."

Tracking the fate of the carbon
For the new study, published in Nature Geoscience, the research team collected core samples of buried sediments from four floodplains in the upper Colorado River Basin in the states of Colorado and New Mexico.

The approximately 3-foot-long, column-shaped samples went deep enough to reach oxygen-starved layers where microbes must switch from doing the microbial equivalent of breathing oxygen to breathing sulfur. In either case, the microbes combine oxygen or sulfur with carbon-based food to produce energy and release either carbon dioxide or sulfur dioxide into the atmosphere. (That sulfur dioxide is responsible for the distinctive smell of oxygen-poor wetlands.)

To identify where in the sediment samples microbes had made the switch, the researchers turned to the Stanford Synchrotron Radiation Lightsource facility. The synchrotron machine generates extremely bright X-ray light that, when shone upon the samples, generates a signal revealing the chemistry of the sulfur. The presence of sulfide minerals indicates where the microbes began making use of sulfur alongside carbon to power their biochemical machinery.

The question was whether the switch to sulfur influenced the carbon sources the microbes ate or left behind. To find out, the researchers relied on unique instrumentation and collaborations within the Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory in Richmond, Washington. With the aid of a very strong magnet, an instrument called a mass spectrometer at the lab characterized the water-soluble organic material.

The tests found that, in contrast to the layers where oxygen was available, leftover carbon compounds in the sediment samples where sulfur had been used for respiration were mostly of the sort that requires more energy to degrade than would be liberated through the degradation itself. Of no use, then, to growing microbes, these carbon compounds had remained within the deeper sediment layers.

Honing models of the carbon cycle
Floodplains, like those sampled in the study, rank among the most common areas globally for the internment of plant and animal matter by water-borne sediments. The oxygen-poor conditions created underground there are known to sequester carbon, but as the study suggests, partly for reasons previously unrecognized and with unforeseen consequences.

For such flood-prone, low-lying areas are by definition close to waterways. Soluble, unused organic material can migrate quite easily into an aerated waterway for subsequent breakdown, triggering algae blooms and other water quality issues while also leading to carbon dioxide production.

Models of how living organisms, the ground, bodies of water and the atmosphere recycle carbon will increasingly need to incorporate key nuances, like the preservation mechanism described in the new Stanford study, in order to inform scientists' understanding as well as policymakers' decisions.

"Getting the constraints right on what really controls the processes of carbon breakdown is essential," said Fendorf. "That's what our study helps illuminate."

Other co-authors on the study, titled "Thermodynamically controlled preservation of organic carbon in floodplains," include Vincent Noel, Sharon Bone and John Bargar of the SLAC National Accelerator Laboratory; Malak Tfaily of the Pacific Northwest National Laboratory; and Kenneth Williams of the Lawrence Berkeley National Laboratory. Funding was provided by the U.S. Department of Energy, the Office of Biological and Environmental Research, the SLAC National Accelerator Laboratory and the Lawrence Berkeley National Laboratory.

CARBON WORLDS
Graphene withstands high pressure, may aid in desalination
La Jolla, CA (SPX) Apr 27, 2017
Professor Klaus Ley, M.D., has been selected as this year's winner of the Eugene M. Landis Award, the Microcirculatory Society's top honor, in recognition of his pioneering work in vascular biology and microcirculation. The microcirculation comprises all the small blood vessels in all tissues and organs and their contents (blood plasma and blood cells). A member of the Microcirculatory Soc ... read more

Related Links
Stanford's School of Earth, Energy and Environmental Sciences
Carbon Worlds - where graphite, diamond, amorphous, fullerenes meet


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

CARBON WORLDS
12 Scientist-Astronaut Candidates Graduate at Embry-Riddle Through Project PoSSUM

Elon Musk teases future plans at TED

Students Taste Sweet Smell of Success in Culinary Challenge

Honeywell And Paragon To Create Life Support Technology For Future NASA Space Missions

CARBON WORLDS
SpaceX makes first US military launch, then lands rocket again

Strike-delayed European rocket launch to go ahead

India to launch GSAT-9 communication satellite on May 5: ISRO

SpaceX launches classified payload for NRO; 1st Stage returns to LZ-1

CARBON WORLDS
Japan aims to uncover how moons of Mars formed

Several drives put opportunity closer to 'Perseverance Valley'

Is Anything Tough Enough to Survive on Mars

How Old are Martian Gullies

CARBON WORLDS
Reach for the Stars: China Plans to Ramp Up Space Flight Activity

China to conduct several manned space flights around 2020

China's cargo spacecraft completes in-orbit refueling

China courts international coalition set up to promote space cooperation

CARBON WORLDS
How Outsourcing Your Satellite Related Services Saves You Time and Money

ViaSat-2 Satellite to Launch on June 1

ESA boosting its Argentine link with deep space

Arianespace, Intelsat and SKY Perfect JSAT sign a new Launch Services Agreement, for Horizons 3e

CARBON WORLDS
Why space dust emits radio waves upon crashing into a spacecraft

Ground Control Satellite Dish Arrives at University of Leicester

Raytheon receives $327M radar contract for U.S. Navy

SES Offers Panoramic Glimpse into the Future of TV with Live Virtual Reality Demo

CARBON WORLDS
SOFIA Confirms Nearby Planetary System Is Similar to Our Own

Nearby Star Confirmed as Good Model of Our Early Solar System

Next Breakthroughs in Exoplanet Discovery

Research Center A Hub For Origins of Life Studies

CARBON WORLDS
The PI's Perspective: No Sleeping Back on Earth!

ALMA investigates 'DeeDee,' a distant, dim member of our solar system

Nap Time for New Horizons

Hubble spots auroras on Uranus









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.