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.

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 July 22, 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 July 22, 2014).

Share This




More Earth & Climate News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 Video provided by AFP
Powered by NewsLook.com
A Centuries' Old British Tradition Is Far from a Swan Song

A Centuries' Old British Tradition Is Far from a Swan Song

AFP (July 19, 2014) As if it weren't enough that the Queen is the Sovereign of the UK and 15 other Commonwealth realms, she is also the owner of all Britain's unmarked swans. Duration: 02:18 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