Microprobe analysis of brine shrimp grown on meteorite extracts J. Kennedy a, * , M.N. Mautner b,c,1 , B. Barry a , A. Markwitz a a National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt, New Zealand b Soil, Plant and Ecological Sciences Division, Lincoln University, New Zealand c Department of Chemistry, University of Canterbury, Christchurch 8001, New Zealand Available online 14 February 2007 Abstract Nuclear microprobe methods have been used to investigate the uptake and distribution of various elements by brine shrimps and their unhatched eggs when grown in extracts of the Murchison and Allende carbonaceous meteorites, which were selected as model space resources. Measurements were carried out using a focussed 2 MeV proton beam raster scanned over the samples in order to obtain the average elemental concentrations. Line scans across the egg and shrimp samples show uptake of elements such as Mg, Ni, S and P which are present in the meteorites. The results confirmed that carbonaceous chondrite materials can provide nutrients, including high levels of the essential nutrient phosphate. The concentrations of these elements varied significantly between shrimp and eggs grown in extracts of the two meteorite types, which can help in identifying optimal growth media. Our results illustrate that nuclear microprobe techniques can determine elemental concentrations in organisms exposed to meteorite derived media and thus help in identifying useful future resources. Ó 2007 Elsevier B.V. All rights reserved. PACS: 29.27.Àa; 29.30.Ep; 87.23.Àn; 91.65.Sn; 87.64.Àt Keywords: Meteorites; Planetary science; Micro-PIXE; Nuclear microprobe techniques 1. Introduction Materials in carbonaceous meteorites contributed to early life and similar materials in asteroids can provide resources for the future colonisation of the Solar system [1]. Both with respect to their contribution to early evolu- tion and for potential future applications, it is of interest to investigate whether or not asteroid/meteorite materials can support life and which of their components can exert nutrient or toxic effects. In previous studies, we found that Martian and carbo- naceous chondrite meteorites contain soil nutrients such as P, N, K and S that can support bacteria, algae and plant tissue cultures and recently, brine shrimp [2–7]. These experiments showed that aqueous extracts of the Murchison C2 carbonaceous meteorite can be utilized as a sole carbon source by microorganisms, as demonstrated by the genetically modified Pseudomonas fluorescence equipped with the lux gene. Nutrient effects are observed also with the soil microorganism Nocardia asteroides that reached populations of up to 5 · 10 7 CFU/ml in meteorite extracts, similar to populations in terrestrial soil extracts [6,7]. Plant tissue cultures of Asparagus officinalis and Sola- num tuberosum (potato) exhibit enhanced pigmentation and some enhanced growth when meteorite extracts are added to partial nutrient media, but inhibited growth when added to full nutrient solution, possibly due to toxic levels of Ni [6,7]. The meteorite extracts lead to large increases in S, Ca, Mg and Fe plant tissue contents as shown by X-ray fluorescence, while P, K and Cl contents show mixed effects. Both microbiological and plant experiments showed that the nutrient and inhibitory effects appear to be 0168-583X/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2007.02.022 * Corresponding author. Fax: +64 4 570 4657. E-mail addresses: j.kennedy@gns.cri.nz (J. Kennedy), m.mautner@ solis1.com (M.N. Mautner). 1 Contact author for astrobiology enquiries. www.elsevier.com/locate/nimb Nuclear Instruments and Methods in Physics Research B 260 (2007) 184–189 NIM B Beam Interactions with Materials & Atoms