PMID- 21707388
OWN - NLM
STAT- MEDLINE
DCOM- 20120305
LR  - 20110628
IS  - 1557-8070 (Electronic)
IS  - 1557-8070 (Linking)
VI  - 11
IP  - 5
DP  - 2011 Jun
TI  - Survival of Bacillus subtilis endospores on ultraviolet-irradiated rover wheels 
      and Mars regolith under simulated Martian conditions.
PG  - 477-85
LID - 10.1089/ast.2011.0615 [doi]
AB  - Endospores of Bacillus subtilis HA101 were applied to a simulated Mars 
      Exploration Rover (MER) wheel and exposed to Mars-normal UV irradiation for 1, 3, 
      or 6 h. The experiment was designed to simulate a contaminated rover wheel 
      sitting on its landing platform before rolling off onto the martian terrain, as 
      was encountered during the Spirit and Opportunity missions. When exposed to 1 h 
      of Mars UV, a reduction of 81% of viable endospores was observed compared to the 
      non-UV irradiated controls. When exposed for 3 or 6 h, reductions of 94.6% and 
      96.6%, respectively, were observed compared to controls. In a second experiment, 
      the contaminated rover wheel was rolled over a bed of heat-sterilized Mars analog 
      soil; then the analog soil was exposed to full martian conditions of UV 
      irradiation, low pressure (6.9 mbar), low temperature (-10 degrees C), and an anaerobic 
      CO(2) martian atmosphere for 24 h to determine whether endospores of B. subtilis 
      on the contaminated rover wheel could be transferred to the surface of the analog 
      soil and survive martian conditions. The experiment simulated conditions in which 
      a rover wheel might come into contact with martian regolith immediately after 
      landing, such as is designed for the upcoming Mars Science Laboratory (MSL) 
      rover. The contaminated rover wheel transferred viable endospores of B. subtilis 
      to the Mars analog soil, as demonstrated by 31.7% of samples showing positive 
      growth. However, when contaminated soil samples were exposed to full martian 
      conditions for 24 h, only 16.7% of samples exhibited positive growth-a 50% 
      reduction in the number of soil samples positive for the transferred viable 
      endospores.
FAU - Kerney, Krystal R
AU  - Kerney KR
AD  - Department of Plant Pathology, University of Florida , Space Life Sciences Lab, 
      Kennedy Space Center, USA.
FAU - Schuerger, Andrew C
AU  - Schuerger AC
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Astrobiology
JT  - Astrobiology
JID - 101088083
RN  - 0 (Soil Pollutants)
SB  - IM
MH  - Bacillus subtilis/*cytology/*radiation effects
MH  - Computer Simulation
MH  - *Extraterrestrial Environment
MH  - *Mars
MH  - Microbial Viability/*radiation effects
MH  - Soil Pollutants/analysis
MH  - Spacecraft/*instrumentation
MH  - Spores, Bacterial/cytology/radiation effects
MH  - *Ultraviolet Rays
EDAT- 2011/06/29 06:00
MHDA- 2012/03/06 06:00
CRDT- 2011/06/29 06:00
PHST- 2011/06/29 06:00 [entrez]
PHST- 2011/06/29 06:00 [pubmed]
PHST- 2012/03/06 06:00 [medline]
AID - 10.1089/ast.2011.0615 [doi]
PST - ppublish
SO  - Astrobiology. 2011 Jun;11(5):477-85. doi: 10.1089/ast.2011.0615.