Featured Research

from universities, journals, and other organizations

Freeze-dried Mats Of Microbes Awaken In Antarctic Streambed, Says U. Of Colorado Study

Date:
August 9, 2005
Source:
University of Colorado at Boulder
Summary:
An experiment in a dry Antarctic stream channel has shown that a carpet of freeze-dried microbes that lay dormant for two decades sprang to life one day after water was diverted into it, said a University of Colorado at Boulder researcher.

CU-Boulder Professor Diane McKnight (blue jacket) and her research colleagues use sandbags to divert water into a streambed in Antarctica that had been dry for 20 years. Dormant bacterial mats popped up the next day.
Credit: Photo courtesy CU-Boulder

An experiment in a dry Antarctic stream channelhas shown that a carpet of freeze-dried microbes that lay dormant fortwo decades sprang to life one day after water was diverted into it,said a University of Colorado at Boulder researcher.

Related Articles


The results showed the resilience of life in the harsh polarenvironment, where temperatures are below freezing for most of the yearand glacial melt water flows for only five to 12 weeks annually, saidProfessor Diane McKnight of CU-Boulder's Institute of Arctic and AlpineResearch. Such research on life in extreme environments is of highinterest to astrobiologists, who consider Antarctica's McMurdo DryValleys an analogue for Mars because of its inhospitable climate andintermittent water flow.

"This was something we did not anticipate," said McKnight,whose research group is working at Antarctica's McMurdo Dry ValleysLong Term Ecological Research, or LTER, site funded by the NationalScience Foundation. "These mats not only persisted for years when therewas no water in the streambed, but blossomed into an entire ecosystemin about a week. All we did was add water."

McKnight gave a presentation on the experiment at theEcological Society of America's 90th Annual Meeting held Aug. 7 to Aug.12 in Montreal.

The river channels under study feature intermittent streamsthat link glaciers to frozen lakes on the valley floor, she said. Thestreambeds contain photosynthetic microbes known as cyanobacteria,which collectively occur as thin, rubbery mat-like structures that canspread several meters across the streambed surface.

The experiment began in the 1994 research season, when theteam used sandbags to divert water from an active streambed in theMcMurdo Dry Valleys into the dry streambed, she said. A time series ofaerial photographs, coupled with carbon isotope analyses of thecyanobacteria that measured variation in atmospheric carbon overdecades, indicated the streambed had been dry for about 20 years.

"After we diverted the water into the channel, photosynthesisbegan the same day and the mats became abundant within a week," shesaid. "This showed us that they had been preserved in a cryptobioticstate."

Over the next several years, the microbial mats in theexperimental channel had higher growth rates than mats in adjacentstreambeds receiving annual summer water flow, she said. The studyshowed the new microbial mats were taking up atmospheric nitrogen at ahigher rate than mats in adjacent streambeds, increasing biomassproductivity, she said. As photosynthetic bacteria, cyanobacteria arebelieved by biologists to be among the first living organisms tocolonize Earth. The mats generally are orange or black and consist of10 to 15 different species of cyanobacteria, she said.

Because of a cooling trend in the McMurdo Dry Valleys, somestreambeds that normally have annual summer flows have been dry inrecent years, McKnight said. In contrast, the Antarctic Peninsula haswarmed nearly 5 degrees Fahrenheit in the past 60 years and has seenthe collapse of several major ice shelves and significant glacialthinning in recent years, according to several international studies.

The McMurdo Dry Valleys region consists of glaciers, openexpanses of barren ground, stream channels and permanently ice-coveredlakes. The life forms inhabiting the area include microorganisms,mosses, lichens and a few groups of invertebrates.

Study collaborators included Cathy Tate of the U.S.Geological Survey, Denver; Ned Andrews of the USGS, Boulder, Colo.; DevNiyogi of the University of Missouri-Rolla; CU-Boulder graduate studentKaren Cozetto; Cathy Welsh and Berry Lyons of Ohio State University;and Douglas Capone of the University of California, Irvine.

The McMurdo Dry Valleys site is one of 26 LTER sites in theworld designated by NSF. Approximately 25 scientists participate inresearch during each field season.


Story Source:

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


Cite This Page:

University of Colorado at Boulder. "Freeze-dried Mats Of Microbes Awaken In Antarctic Streambed, Says U. Of Colorado Study." ScienceDaily. ScienceDaily, 9 August 2005. <www.sciencedaily.com/releases/2005/08/050809064541.htm>.
University of Colorado at Boulder. (2005, August 9). Freeze-dried Mats Of Microbes Awaken In Antarctic Streambed, Says U. Of Colorado Study. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2005/08/050809064541.htm
University of Colorado at Boulder. "Freeze-dried Mats Of Microbes Awaken In Antarctic Streambed, Says U. Of Colorado Study." ScienceDaily. www.sciencedaily.com/releases/2005/08/050809064541.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) — Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) — A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) — A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Yellow-Spotted Turtles Rescued from Trafficking

Yellow-Spotted Turtles Rescued from Trafficking

Reuters - Light News Video Online (Nov. 24, 2014) — Hundreds of Amazon River turtles released into the wild in Peru. Sharon Reich reports. Video provided by Reuters
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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