Stereo-Specific Glucose Consumption May Be Used to Distinguish Between Chemical and Biological Reactivity on Mars: A Preliminary Test on Earth

• DOI: 10.1089/ast.2008.0315
• Publication Date: 2009-06-30T19:36:02Z
• Authors: Henry J. Sun; Vienna Saccomanno; Brian Hedlund; Christopher P. McKay
• Keywords: Astrophysics and Astronomy; 0303 health sciences; Bacteria; Extraterrestrial Environment; Earth, Planet; Organic Chemistry; The Sun and the Solar System; Mars (Planet) – Surface; Fungi; Life Sciences; Mars; Stereoisomerism; 03 medical and health sciences; Glucose; Other Life Sciences; Exobiology; Organic compounds; Mars surface samples; Life on other planets; Oxidation-Reduction

Two alternative hypotheses explain the degradation of organics in the Viking Labeled Release experiment on Mars. Either martian soil contains live indigenous microorganisms or it is sterile but chemically reactive. These two possibilities could be distinguished by the use of pure preparations of glucose isomers. In the laboratory, selected eukaryotes, bacteria, and archaea consumed only D-glucose, not L-glucose, while permanganate oxidized both isomers. On Mars, selective consumption of either D- or L-glucose would constitute evidence for biological activity.