Wallis_AbSciCon 2004

Astrobiology Missions

Search for Microbiology in Cryogenically-collected Stratospheric Particles from Space

Max K. Wallis*, N. Chandra Wickramasinghe, Shirwan Al-Mufti, Norimune Miyake, Cardiff Centre for Astrobiology (CCAB), Cardiff University UK, , , Milton Wainwright,Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield,S10 2TN,UK, , Brig Klyce,Astrobiology Research Trust (ART), , J V Narlikar, Inter-University Centre for Astronomy and Astrophysics (IUCAA), India,

Volumes of air from the upper stratosphere collected via balloon-carried cryogenic equipment have been found to trap interplanetary micro-particles (1). Specimens are extracted under clean and sterile conditions. Collection from altitudes up to 41km avoids nearly all particles rising from the troposphere and allows a check on them, so that previously uncertain types of cosmic dust (2) may be identified. Fluffy smoke-like particles with delicate protuberances have been collected, demonstrating that the technique handles particle matter very gently. The samples contain types of interplanetary dust particles (IDPs) previously identified as cometary dust aggregates, asteroidal layer silicates and iron compounds. Particles of order 10m in size are generally single spheres or conglomerates or lattice silicates. Some mineral composites are highly porous and composed of micron-sized crystals, but other fluffy composities have components down to the resolution limit (~ 0.05m). The SEM/EDX analysis also shows carbonaceous material components within the composites. Organic composites are seen as clumps of evenly-sized spheres, shown in biochemical tests (anionic and cationic fluorescing dyes) to comprise dead and living cocci (1). Further work has succeeded in culturing particular organisms (3). A class of larger spheres (5-15m) are spore-like, often with damage cracks and attached mineral particles. Rod-like particles come singly or attached to larger 'spores' and from m's to over 10m long. Further studies of the spore-like shells and and clumps containing viable microorganisms are underway, to determine mineralogical and isotopic associations with the chondritic IDPs.

References

1. The detection of living cells in stratospheric samples, Melanie J. Harris , N.C. Wickramasinghe, David Lloyd, J.V. Narlikar, P. Rajaratnam,Michael P. Turner, S. Al-Mufti, Max K. Wallis, S. RamaduraiF. Hoyle, 2002, in Instruments, Methods and Missions for Astrobiology IV, ed. R.B. Hoover et al., Proc. SPIE Vol. 4495,192-198 [also

2. Microparticle studies by sampling techniques, D E Brownlee, Ch. 5 of Cosmic Dust (ed. J A M McDonnell), Wiley, 1978.

3. Microorganisms cultured from stratospheric air samples obtained at 41km, M. Wainwright, N.C. Wickramasinghe, J.V. Narlikar, P. Rajaratnam, FEMS Microbiol. Lett. 218 (2003) 161-165.

Acknowledgement

We are grateful to the Indian Space Research Organisation for making available ISRO's state of the art cryogenic sampler equipment together with ultraclean systems developed by ISRO for this experiment. Professor J V Narlikar is overall leader of the project.