New Rochelle, May 15, 2007 - Researchers exploring the possibility of finding life forms on Mars can look to diverse populations of microorganisms found to be living in a similar environment underneath the Antarctic polar ice cap, as described in the April issue (Volume 7, Number 2) of Astrobiology, a peer-reviewed journal published by Mary Ann Liebert, Inc. The paper is available free online at www.liebertpub.com/ast.

A team of scientists led by Dr. David A. Gilichinsky, from the Russian Academy of Sciences, Pushchino, and including colleagues from the University of Otago, New Zealand (Dunedin), NASA Ames Research Center, the University of Washington (Seattle), Moscow State University, Florida State University (Tallahassee), and Michigan State University (East Lansing), analyzed samples of permafrost--permanently frozen sediment--collected from 20 boreholes drilled at five sites in the Dry Valleys of Antarctica.

In the paper entitled, "Microbial Populations in Antarctic Permafrost: Biodiversity, State, Age, and Implication for Astrobiology," the authors describe the presence of diverse populations of bacteria (both aerobic and anaerobic bacteria at levels up to 10⁵/gram of dry soil), cyanobacteria, green algae, yeasts, and fungi. Although the number of bacteria decreases with the age of the permafrost sample, the diversity of species does not change.

Based on the documented ages of the permafrost regions from which these cores were removed--perhaps more than 5 million years old--these findings represent the oldest viable microorganisms discovered in permafrost on Earth.

The authors propose that the similarity in environment between permafrost and extraterrestrial habitats--mainly isolation, stability, and dryness--makes these surviving microbes and the Antarctic permafrost a good model for studying possible martian ecosystems associated with frozen regolith. "This study demonstrates the importance of permafrost as a cryopreservant for microbial biosignatures," says journal Editor, Sherry L. Cady, Ph.D., Associate Professor in the Department of Geology at Portland State University. "Antarctica permafrost provides a unique opportunity to demonstrate just how long dormant frozen life could survive in deposits that are considered one of the closest analogs of a possible Mars ecosystem."

Astrobiology is an authoritative peer-reviewed journal published bimonthly in print and online. The Journal provides a forum for scientists seeking to advance our understanding of life's origins, evolution, distribution and destiny in the universe. A complete table of contents and a complimentary sample issue may be viewed online at www.liebertpub.com/AST.

Astrobiology is the leading peer-reviewed journal in its field. To promote this developing field, the Journal has teamed up with The Astrobiology Web to highlight one outstanding paper per issue of Astrobiology. This paper is available free online at www.liebertpub.com/ast and to visitors of The Astrobiology Web at www.astrobiology.com.

Mary Ann Liebert, Inc., is a privately held, fully integrated media company known for establishing authoritative peer-reviewed journals in many promising areas of science and biomedical research. Its biotechnology trade magazine, Genetic Engineering & Biotechnology News (GEN), was the first in its field and is today the industry's most widely read publication worldwide. A complete list of the firm's 60 journals, books, and newsmagazines is available at www.liebertpub.com.

Contact: Vicki Cohn, Mary Ann Liebert, Inc., (914) 740-2100, ext. 2156, vcohn@liebertpub.com

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Contents

• Microbial Populations in Antarctic Permafrost: Biodiversity, State, Age, and Implication for Astrobiology
• Microbial Diversity of Indian Ocean Hydrothermal Vent Plumes: Microbes Tolerant of Desiccation, Peroxide Exposure, and Ultraviolet and gamma-Irradiation
• Chemotrophic Filamentous Microfossils from the Hollard Mound (Devonian, Morocco) as Investigated by Focused Ion Beam
• Observations from a 4-Year Contamination Study of a Sample Depth Profile Through Martian Meteorite Nakhla
• Carbonaceous Cherts in the Barberton Greenstone Belt and Their Significance for the Study of Early Life in the Archean Record
• The Potential for Lithoautotrophic Life on Mars: Application to Shallow Interfacial Water Environments
• Nitrogen Fixation on Early Mars and Other Terrestrial Planets: Experimental Demonstration of Abiotic Fixation Reactions to Nitrite and Nitrate
• Rainbows, Polarization, and the Search for Habitable Planets
• Chiral Symmetry Breaking and Complete Chiral Purity by Thermodynamic-Kinetic Feedback Near Equilibrium: Implications for the Origin of Biochirality