Location
University of Nevada Las Vegas, Student Union Ball Room
Start Date
6-8-2009 9:30 AM
End Date
6-8-2009 12:00 PM
Description
Ability of Martian soil to degrade carbohydrates, shown by the Viking mission, has two interpretations. One possibility is that the soil harbors living microorganisms. Alternatively, the soil is sterile but chemically oxidizing, i.e. it is laden with photochemical oxidants. It was shown by REU research last summer that these two possibilities can be distinguished by the use of glucose enantiomers. Life is selective: Earth organisms use D-glucose, but ignore Lglucose. This stereo selectivity is absent in chemical reactions. The goal of this project is to test if xylose, a five carbon sugar, is also suitable for chiral life detection. Mixed microbial cultures were raised from various soils (Jordan, the Mojave Desert, and the Atacama Desert). Added D- and L-xylose were monitored over time. Results show that terrestrial microorganisms utilize only Dxylose, not L-xylose, confirming that like glucose, xylose is a suitable substrate for Martian life detection.
Keywords
Chemical oxidation; Extraterristrial life; Mars; Martian soils; terrestrial microorganisms; Viking mission; Xylose
Disciplines
Microbiology | Soil Science | The Sun and the Solar System
Language
English
Martian life detection with xylose enantiomers
University of Nevada Las Vegas, Student Union Ball Room
Ability of Martian soil to degrade carbohydrates, shown by the Viking mission, has two interpretations. One possibility is that the soil harbors living microorganisms. Alternatively, the soil is sterile but chemically oxidizing, i.e. it is laden with photochemical oxidants. It was shown by REU research last summer that these two possibilities can be distinguished by the use of glucose enantiomers. Life is selective: Earth organisms use D-glucose, but ignore Lglucose. This stereo selectivity is absent in chemical reactions. The goal of this project is to test if xylose, a five carbon sugar, is also suitable for chiral life detection. Mixed microbial cultures were raised from various soils (Jordan, the Mojave Desert, and the Atacama Desert). Added D- and L-xylose were monitored over time. Results show that terrestrial microorganisms utilize only Dxylose, not L-xylose, confirming that like glucose, xylose is a suitable substrate for Martian life detection.
Comments
Abstract & poster