Featured Research

from universities, journals, and other organizations

Carbon cycle: Four cells turn seabed microbiology upside down

Date:
March 27, 2013
Source:
Aarhus University
Summary:
With DNA from just four cells, researchers reveal how some of the world's most abundant organisms play a key role in carbon cycling in the seabed.

The core sample has just been brought up from the bottom of the Bay of Aarhus and is being cut up. The researchers find archaea in the samples, which -- to their great surprise -- turn out to live on protein degradation.
Credit: Bo Barker Jorgensen

Single-celled archaea are invisible to the naked eye, and even when using a microscope, great care must be taken to observe them. An international team of researchers led by the Center for Geomicrobiology, Aarhus University, Denmark, has nevertheless succeeded in retrieving four archaeal cells from seabed mud and mapping the genome of each one.

"Until now, nobody knew how these widespread mud-dwelling archaea actually live. Mapping the genome from the four archaeal cells shows they all have genes that enable them to live on protein degradation," says Professor Karen Lloyd, now at the University of Tennessee, and leading author of the ground-breaking results published in the journal Nature.

Scientists previously thought that proteins were only broken down in the sea by bacteria, but archaea have now turned out to be important new key organisms in protein degradation in the seabed. Proteins actually make up a large part of the organic matter in the seabed and -- since the seabed has the world's largest deposit of organic carbon -- archaea thus appear to play an important and previously unknown role in the global carbon cycle.

Like a grain of sand on the beach

Archaea are some of the most abundant organisms in the world, but very few people have ever heard of them. They were originally discovered in extreme environments such as hot springs and other special environments like cow stomachs and rice paddies, where they form methane. In recent years, however, researchers have realised that archaea make up a large part of the microorganisms in the seabed, and that the seabed is also the habitat of the majority of the world's microorganisms.

"A realistic estimate is that archaea are the group of organisms with the most individuals in the world. In fact, there are more archaea than there are grains of sand on the beaches of the whole world. If you bury your toes right down in the mud in the seabed, you'll be in touch with billions of archaea," says Professor Bo Barker Jψrgensen, Director of the Center for Geomicrobiology.

New technology links function and identity

This is the first time that scientists have succeeded in classifying archaeal cells in a mud sample from the seabed and subsequently analysing the genome of the cells, thereby revealing what the organisms are and what they live on.

"At present, we can't culture these archaea or store them in the laboratory, so this rules out the physiological tests usually carried out by the microbiologists. We've therefore worked with cell extraction, cell sorting, and subsequent mapping of the individual cell's combined genetic information -- that's to say its genome. This is a new approach that can reveal both a cell's identity and its lifestyle," says Professor of Microbiology Andreas Schramm, affiliated with the Center for Geomicrobiology.

The method opens up a new world of knowledge for microbiologists, who can now study an individual microorganism just as zoologists study an individual mouse. Microbiologists have been hoping for this for a long time. Until now, they have only been familiar with the life processes of less than 1% of the world's microorganisms -- those they can culture in a laboratory. The new method provides opportunities for studying the remaining 99% directly from nature.

"Applying this novel technique to marine sediments means we don't have to wait a thousand years for archaea to grow in lab to analyze their genomes -- we can just sequence them directly from the environment. In future, this method will no doubt reveal new, unknown functions of microorganisms from many different environments, concludes Postdoctoral Fellow Dorthe Groth Petersen.


Story Source:

The above story is based on materials provided by Aarhus University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Karen G. Lloyd, Lars Schreiber, Dorthe G. Petersen, Kasper U. Kjeldsen, Mark A. Lever, Andrew D. Steen, Ramunas Stepanauskas, Michael Richter, Sara Kleindienst, Sabine Lenk, Andreas Schramm, Bo Barker Jψrgensen. Predominant archaea in marine sediments degrade detrital proteins. Nature, 2013; DOI: 10.1038/nature12033

Cite This Page:

Aarhus University. "Carbon cycle: Four cells turn seabed microbiology upside down." ScienceDaily. ScienceDaily, 27 March 2013. <www.sciencedaily.com/releases/2013/03/130327144120.htm>.
Aarhus University. (2013, March 27). Carbon cycle: Four cells turn seabed microbiology upside down. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2013/03/130327144120.htm
Aarhus University. "Carbon cycle: Four cells turn seabed microbiology upside down." ScienceDaily. www.sciencedaily.com/releases/2013/03/130327144120.htm (accessed April 16, 2014).

Share This



More Plants & Animals News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) — The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
In Washington, a Push to Sterilize Stray Cats

In Washington, a Push to Sterilize Stray Cats

AFP (Apr. 14, 2014) — To curb the growing numbers of feral cats in the US capital, the Washington Humane Society is encouraging residents to set traps and bring the animals to a sterilization clinic, after which they are released.. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
After Attack, Officials Kill 5 Bears in Florida

After Attack, Officials Kill 5 Bears in Florida

AP (Apr. 14, 2014) — Florida wildlife officials say they have killed five bears following an attack on a woman in a suburban subdivision in central Florida. Forty-five year-old Terri Frana was attacked by a large bear in her driveway Saturday. (April 14) Video provided by AP
Powered by NewsLook.com
Uruguay Opens Its First Cannabis Library

Uruguay Opens Its First Cannabis Library

AFP (Apr. 13, 2014) — Uruguay opened its first Cannabis Library in Montevideo on Saturday, where people can come and read books on cannabis or take classes on how to grow the plant or even how to cook with it. Duration: 01:20 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins