Navigation Links
Freeze-dried mats of microbes awaken in Antarctic streambed

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.

The results showed the resilience of life in the harsh polar environment, where temperatures are below freezing for most of the year and glacial melt water flows for only five to 12 weeks annually, said Professor Diane McKnight of CU-Boulder's Institute of Arctic and Alpine Research. Such research on life in extreme environments is of high interest to astrobiologists, who consider Antarctica's McMurdo Dry Valleys an analogue for Mars because of its inhospitable climate and intermittent water flow.

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

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

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

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

"After we diverted the water into the channel, photosynthesis began the same day and the mats became abundant within a week," she said. "This showed us that they had been preserved in a cryptobiotic state."

Over the next several years, the microbial mats in the experimental channel had higher growth rates than mats in adjacent streambeds receiving annual summer water flow, she said. The study showed the new microbial mats were taking up atmospheric nitrogen at a higher rate than mats in adjacent streambeds, increasing biomass productivity, she said. As photosynthetic bacteria, cyanobacteria are believed by biologists to be among the first living organisms to colonize Earth. The mats generally are orange or black and consist of 10 to 15 different species of cyanobacteria, she said.

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

The McMurdo Dry Valleys region consists of glaciers, open expanses of barren ground, stream channels and permanently ice-covered lakes. 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.; Dev Niyogi of the University of Missouri-Rolla; CU-Boulder graduate student Karen 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 the world designated by NSF. Approximately 25 scientists participate in research during each field season.


'"/>

Source:University of Colorado at Boulder


Related biology news :

1. W.M. Keck Foundation funds study of friendly microbes
2. Yellowstone microbes fueled by hydrogen, according to U. of Colorado study
3. Harnessing microbes, one by one, to build a better nanoworld
4. Leprosy microbes lead scientists to immune discovery
5. Could microbes solve Russias chemical weapons conundrum?
6. Proteomics brings researchers closer to understanding microbes that produce acid mine drainage
7. Understanding the oceans microbes is key to the Earths future
8. Wisconsin scientists discover a master key to microbes pathogenic lifestyles
9. New method for identifying microbes
10. EGF receptor activation prevents microbes from going more than skin deep
11. Gut microbes partnership helps body extract energy from food, store it as fat
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:12/22/2016)... , December 22, 2016 SuperCom ... of secure solutions for the e-Government, Public Safety, HealthCare, and Finance ... of SuperCom, has been selected to implement and deploy a community-based ... Northern California , further expanding its presence in ... This ...
(Date:12/16/2016)... 2016 Research and Markets has announced the ... Forecast to 2021" report to their offering. ... The biometric vehicle access system ... CAGR of 14.06% from 2016 to 2021. The market is estimated ... reach 854.8 Million by 2021. The growth of the biometric vehicle ...
(Date:12/15/2016)... , Dec. 15, 2016 Advancements ... experience, health wellness and wellbeing (HWW), and ... in three new passenger vehicles begin to ... gesture recognition, heart beat monitoring, brain wave ... facial monitoring, and pulse detection. These will ...
Breaking Biology News(10 mins):
(Date:1/21/2017)...   Boston Biomedical , an industry leader in ... stemness pathways, today presented data from two clinical studies ... American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium ... In a Phase Ib/II study of napabucasin – ... stemness pathways by targeting STAT3 – colorectal cancer (CRC) ...
(Date:1/20/2017)... January 20, 2017 http://www.Financialbuzz.com ... one of leading causes of death worldwide. There were ... number of cancer related deaths increased gradually over time, ... incidence rate of various cancers continues to drive demand ... report by Global Market Insights, Inc. cancer biological therapy ...
(Date:1/19/2017)... and HOUSTON , Jan. 19, ... today announced the formation of its Medical/Clinical Advisory ... and industry veterans who enhance the range and ... accelerates development of its novel prenatal diagnostic tests.  ... clinical and strategic guidance for the company,s product ...
(Date:1/19/2017)... ... January 19, 2017 , ... November Research ... leading biopharmaceutical and medical device manufacturers and regulators, is proud to announce the ... 11-compliant email client designed to provide product vigilance departments with the flexibility and ...
Breaking Biology Technology: