Relicts of Ancient Cellular Biochemistry in High-CO2 Subsurface Ecosystems

Introduction

The biological conversion of inorganic to organic carbon, autotrophic CO2 fixation, is arguably the most important biosynthetic process on Earth. Having been established early in the Archean Eon, a period characterized by an atmosphere rich in CO2, this metabolism helped spark and fuel the evolution of early microbial life.

CO2 and Microbial Life

Mounting evidence suggests that exceedingly high levels of CO2 select for energetically efficient CO2 fixation pathways, immensely affecting carbon cycling. We hypothesize that CO2-rich subsurface ecosystems still harbor microbes that prefer or even require extremely high CO2 concentrations; we refer to these microbes as carbodioxyphiles.

Impact on Microbial Metabolism

Accordingly, elevated CO2 levels would impact the thermodynamics of the microbial central carbon metabolism, enhancing autotrophy and hindering remineralization of organic matter by heterotrophs.

Research Objectives

To this end, we will study microbial life in CO2-rich subsurface environments and elucidate ancient metabolic pathways rendered obsolete by the CO2 levels of most modern environments. Each of the research team’s members has contributed to prior breakthroughs in:

1. Novel autotrophic pathways
2. Environmental genomics
3. Metabolomics
4. The biogeochemistry of deep subsurface environments

Establishing optimal synergy in this wealth of expertise and experience, we will describe novel modes of microbial carbon fixation in CO2-rich settings and elucidate the importance of carbodioxyphily for microbial evolution.

Unique Research Environment

Archean Park will provide a unique window through which to study a new mode of cellular biochemistry, the relicts of primordial carbon fixation, and Earth’s earliest carbon cycle.

Expected Outcomes

We will comprehensively characterize the metabolic mechanisms exploited by microbes to achieve evolutionary dominion in these relict environments. Our findings will stimulate biotechnological and geotechnical innovations ranging from enhanced autotrophic biomass production to improved carbon sequestration and storage.