Presentation Abstract

Abstract Title: Identification and Survival of Isolates Collected from the Mars Rover, Curiosity
Author Block: S. Smith1, J. N. Benardini, III2, D. Anderl1, M. Ford3, W. Schubert2, L. Deveaux4, S. E. Childers5, A. Paszczynski1;
1Univ. of Idaho, Moscow, ID, 2Jet Propulsion Lab., CalTech, Pasadena, CA, 3Idaho State Univ., Pocatello, ID, 4South Dakota Sch. of Mines and Technology, Rapid City, SD, 5Colby Coll., Waterville, ME
Presentation Number: 1373
Poster Board Number: 1373
Keywords: Mars Science Laboratory,Planetary protection,Extreme environments
Abstract: Planetary protection is governed by the Outer Space Treaty which includes the practice of protecting planetary bodies from contamination by Earth life (forward contamination). Although studies are constantly expanding our knowledge about life in extreme environments, it is still unclear whether organisms from Earth can survive and grow in a Martian environment where there is intense radiation, high oxidation potential, extreme desiccation, and limited nutrients. Knowing if microorganisms survive in conditions simulating those on the Martian surface is paramount to addressing whether these microorganisms could pose a risk to future challenging planetary protection missions. The objectives of this study were to 1) Identify cultivable microbes collected from the surfaces of the MSL, Curiosity; 2) Distinguish those microorganisms that can utilize electron acceptors known to be available on Mars, and 3) Determine microbial survival after exposure to Mars-like conditions.   Organisms were collected during MSL’s planetary protection implementation campaign. Isolates were identified and characterized using standard culturing and molecular techniques. Results show that a 62% of the 377 organisms identified are related to members of the Bacillus genus although surprisingly, 31% belong to non-spore-forming genera. These isolates comprise 25 genera and 65 species. Data suggests that 19 of these organisms are able to reduce potential growth substrates, such as perchlorate and sulfate, found on Mars. Many isolates have shown resistance to desiccation (78%), and UVC radiation. Moreover, 94% of the isolates can grow in the presence of elevated salt conditions (≥10% NaCl) and 35% grow at low temperatures (4C). More strikingly, 11% of isolates could survive under multiple extreme conditions. Results from this study are yielding details about the microbes that inhabit the surfaces of spacecraft after microbial reduction. On a broader level, this study will help gauge whether microorganisms from Earth pose a forward contamination risk that could impact future life detection and sample return missions. The overall outcome of this study will provide knowledge about the hardiest of organisms on the spacecraft and could benefit the development of cleaning and sterilization technologies to prevent forward contamination.