Cuatro Cienegas Stromatolite Project 
Understanding the mechanisms that link genomes to biomes is one of the most exciting challenges facing modern biology. In this project we test a set of ideas that connect environmental phosphorus (P) supplies to dynamics and structure of microbial communities via mechanisms associated with the structure and function of the genes that control ribosome biogenesis (the rrn genes and their regulatory domains). To test this “Growth Rate Hypothesis” (GRH), we are performing lab and field experiments involving microorganisms and microbial communities in springs and saline ponds in the Cuatro Ciénegas basin (México; CCB) where previous work has found both highly biodiverse microbial communities and severe in situ P-limitation

Pumice Islands in Bariloche, Argentina                     
Initial study to broaden an emerging collaboration between Jim Elser’s ecological laboratory at ASU and the Laboratorio de Limnología of Drs. Balseiro and Modenutti in Argentina and to build a new collaboration between Janet Siefert  (bioinformatician) with these Argentinian colleagues, bringing a new genomics perspective to the limnological studies ongoing in the Laboratorio de Limnología. There is urgent need and unique scientific opportunity to characterize the biogeochemical and ecological impacts of the 4 June 2011 (and ongoing) Puyehue-Cordón Caulle eruption on lakes of Argentine (and Chilean) Patagonia.  Other work being pursued via funding from the Argentinian government is examining limnological effects of ash inputs on the light environment (due to shading) and nutrient (N, P) availability (both positive and negative), as well as on the food web, both microbial (protozoan) and metazoan (crustaceans). 

Bacillus coahuilensis and its interesting relatives 
Progress in sequencing technology is revolutionizing our approach to microbiological discovery. For the evolutionary biologist/biogeochemist, the ability to sequence and re-sequence microbial genomes offers a window into genomic adaptation at the level of naturally imposed environmental constraints. We are utilizing a pangenomic strategy to construct a snapshot of the genetic reservoir and gene flux of a globally distributed, monophyletic marine heterotroph. Previous results provided evidence of a unique adaptive response in a member of this lineage and using that gene transfer event as a metric, we investigated it’s presence or absence in three related isolates that are functionally relevant constituents in marine (and analogous terrestrial) systems in one continental regime. This pangenome study extends the opportunity to go beyond the relevance of gene transfer in these isolates to understanding flux and function for the lineage on a global scale. Our hypothesis: Understanding the pangenome of an ancient heterotroph allows a view into the importance of the genetic repertoire for adaptive processes and the colonization of microbial life in general.  It is the previously observed qualities of this lineage with regards to its monophyly, dynamicity in genome architecture, key horizontal gene transfer events attributable to environment, and its ubiquitous global presence in these similar environments that make it a choice candidate for an exobiologically relevant pan-genome.