2002 Annual Science Report
Pennsylvania State University Reporting | JUL 2001 – JUN 2002
GEOPULSE (Gene Expression of Observations for Planetary Life Study)
The goal of this project was to form links between microbial geobiology and genomics.
Particularly exciting results came from the investigation of anaerobic methane oxidation. We developed a method to directly couple isotopic and phylogenetic analysis of cells. As reported in two papers, we were able to link the uncultured archaeal groups ANME-1 and ANME-2 to the process of anaerobic methane oxidation.
An exciting area of research has been the continuing use of complete genome sequences to explore microbial phylogenetics. This year, we explored the effects of lateral gene transfer to the results and explored the potential to use partial genome data for tree building. We also investigated the relations of animal phyla producing a tree supporting the Coelomata over the Ecdysozoa. Our newest results are related to the phylogenetic relations within the Archaea. Our latest tree includes a number of methanogens – providing a view that the group (along with Archaeoglobus) forms a clade in contrast to the ordering suggested by rRNA analysis. This is a very important result as it provides a node on the tree that can be linked with the geochemical process of methanogenesis.
We have also been looking at the geomicrobiological signatures of life. We have conducted a number of experiments investigating the degree of anaerobic methane oxidation possible by a number of known methanogenic and micro-methanogenic Archaea, including members of the archaeal sulfate-reducing genera Archaeoglobus. Furthermore, a paper on carbon isotopic fractionation has been submitted to Organic Geochemistry, while further research into carbon isotopic fractionation by methanogens proceeds this summer. We are also working on a new FISH-SIMS method for measuring trace metals in cells from natural environments, a project that may provide a method for inferring biochemical attributes of uncultured cells. Finally, Pyrobaculum aerophilum has been shown to extract Tunsten from basalt at 100°C.
PROJECT MEMBERS:Christopher House
RELATED OBJECTIVES:Objective 4.0
Expand and interpret the genomic database of a select group of key microorganisms in order to reveal the history and dynamics of evolution.
Define how ecophysiological processes structure microbial communities, influence their adaptation and evolution, and affect their detection on other planets.
Identify the environmental limits for life by examining biological adaptations to extremes in environmental conditions.