Survivability of Bacillus subtilis Spores After
Impact- Mediated Ejection from a Planet
This project tested the survivability of bacterial spores during the impact of a meteorite on a planet and ejection of part of the crust containing the organisms, simulated using the 2-stage gas gun at NASA’s Ames research center. A 1/4-inch aluminum sphere impacted a granite slab infused with Bacillus subtilis spores at 5.4 km/sec. The spalled pieces were collected in layers of polyurethane foam, which were then examined for the presence of viable B. subtilis spores. Colonies were subjected to molecular fingerprinting by RAPD-PCR analysis to confirm the identity of the spores. The results of this experiment indicate that the spores did survive the impact, and that those spores found were the ones placed on the granite, and not contamination.
Methods
Above: Steps in isolation of bacteria from impact: 1. Layers of foam in the gun; 2. Tracks in the foam; 3. Grid drawn around tracks; 4. Cutting of the foam; 5. Track visible in a foam block; 6. Foam blocks in test tubes. Bacteria then tested for amylase activity (on starch agar) and chloramphenicol resistance, before undergoing RAPD-PCR to confirm the strain was that placed on the block
Conclusions
1) The experiment was a success, indicating that bacteria can survive the impact and ejection from a planet.
2) This implies (along with other data) that Earth is not a closed biological system, i.e. life can travel from one planet to another.
Author: Tovy Haber Kamine, CBS Trainee, SLSTP 2004
Yale University, New Haven, CT
Principal Investigators: Wayne Nicholson, Ph.D. and Patricia Fajardo-Cavazos, Ph.D.
University of Florida/SLSL Kennedy Space Center
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