Planetary Bioresources and Astroecology 1. Planetary Microcosm Bioassays of Martian and Carbonaceous Chondrite Materials: Nutrients, Electrolyte Solutions, and Algal and Plant Responses

Abstract

The biological fertilities of planetary materials can be assessed using microcosms based on materials in martian and carbonaceous chondrite meteorites. Their biological fertilities are rated based on soluble electrolyte nutrients, on the growth of mesophile and cold-tolerant algae, and of plant tissue cultures. The Murchison CM2 carbonaceous chondrite meteorite and DaG 476 martian shergottite contain high levels of water-extractable Ca, Mg, and SO4–S. The martian meteorites DaG 476 and EETA 79001 also contain high levels of extractable nutrients NO3–N (0.013–0.017 g kg−1) and PO4–P (0.019–0.046 g kg−1). The yields of most of the water-extractable electrolytes vary little under wide planetary conditions, but the longterm extractable phosphate increases significantly under a CO2 atmosphere. The yields of algae and plant tissue cultures correlate with extractable NO3–N and PO4–P that are the limiting nutrients. Mesophilic algae and Asparagus officinalis are useful bioassay agents. A fertility rating system based on meteorite microcosms is proposed. The fertilities are rated as martian basalts \u3e terrestrial basalt, agricultural soil \u3e carbonaceous chondrites, lava ash \u3e cumulate igneous rocks. The extractable materials in Murchison show that internal solutions in carbonaceous asteroids (3.8 mol L−1 electrolytes and 10 g L−1 organics) can support microorganisms in early solar systems, and that carbonaceous asteroids and martian basalts can serve as future for substantial populations in the Solar System