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Astrobiology (general): October 2011


Comparative Survival Analysis of Deinococcus Radiodurans and the Haloarchaea Natrialba Magadii and Haloferax Volcanii, Exposed to Vacuum Ultraviolet Irradiation

Ximena C. Abrevaya, Ivan G. Paulino-Lima, Douglas Galante, Fabio Rodrigues, Pablo J.D. Mauas, Eduardo Corton, Claudia de Alencar Santos Lage
(Submitted on 29 Sep 2011)

The haloarchaea Natrialba magadii and Haloferax volcanii, as well as the radiation-resistant bacterium Deinococcus radiodurans, were exposed to vacuum-UV (V-UV) radiation at the Brazilian Synchrotron Light Laboratory (LNLS). Cell monolayers (containing 105 - 106 cells per sample) were prepared over polycarbonate filters and irradiated under high vacuum (10-5 Pa) with polychromatic synchrotron radiation. N. magadii was remarkably resistant to high vacuum with a survival fraction of ((3.77 ± 0.76) x 10-2), larger than the one of D. radiodurans ((1.13 ± 0.23) x 10-2). The survival fraction of the haloarchaea H. volcanii, of ((3.60 ± 1.80) x 10-4), was much smaller. Radiation resistance profiles were similar between the haloarchaea and D. radiodurans for fluencies up to 150 J m-2. For fluencies larger than 150 J -2 there was a significant decrease in the survival of haloarchaea, and in particular H. volcanii did not survive. Survival for D. radiodurans was 1% after exposure to the higher V-UV fluency (1350 J m-2) while N. magadii had a survival lower than 0.1%. Such survival fractions are discussed regarding the possibility of interplanetary transfer of viable micro-organisms and the possible existence of microbial life in extraterrestrial salty environments such as the planet Mars and the Jupiter's moon Europa. This is the first work reporting survival of haloarchaea under simulated interplanetary conditions.

Full paper

Comments: Draft version (without figures), Accepted for publication in Astrobiology
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Citeas: arXiv:1109.6590v1 [astro-ph.EP]
Submission history
From: Ximena Celeste Abrevaya [view email]
[v1] Thu, 29 Sep 2011 17:02:52 GMT (131kb)

The Call for Session Topics and Session Organizers for AbSciCon 2012 has been extended until OCTOBER 15.

The Astrobiology Science Conference (AbSciCon) relies on input from the astrobiology community in developing the conference program. The organizing committee is currently seeking nominations for session, symposium and workshop topics. The deadline for session nominations has been extended to October 15, 2011.

To submit your session topic, visit the conference website at:
http://abscicon2012.arc.nasa.gov/

KEY DATES

September 1, 2011 - Call for Session Topics/Organizers
October 15, 2011 - SESSION TOPIC PROPOSAL DEADLINE
November 15, 2011 - Call for Abstracts
January 31, 2012 - ABSTRACT DEADLINE
March 1, 2012 - Conference Program posted
March 31, 2012 - Pre-registration deadline
April 16-20, 2012 - ASTROBIOLOGY SCIENCE CONFERENCE 2012

Source: NAI newsletter