Breakfast

Introduction & Welcome

Dr. Masaru Nobu

"Hydrogen: The Fulcrum in Key Evolutionary Steps of Life on Earth"

Life, from its origin to the present, has relied on the process of "pushing" electrons to harness energy and build cells. Hydrogen gas (H2), the simplest and smallest electron source available to biology, has supplied electrons to life throughout our four-billion-year history. In this presentation, I will introduce my perspective on how H2 likely drove life’s success using a mixture of current theories and recent findings from my group. In seafloor hydrothermal vents, where life is hypothesized to have emerged, hot alkaline (high-pH) fluids continuously released streams of H2 generated through a hydrothermal geochemical process known as “serpentinization”. Minerals in these vent systems could abiotically transfer electrons from H2 to inorganic carbon (CO2 and carbonates) – this was one of the first electron flows encountered by life and served as the foundation upon which primordial metabolism evolved. Reflecting this, life’s last universal common ancestor (LUCA) is theorized to have been capable of harnessing energy from H2 through a metabolism mimicking mineral catalysts, “acetogenesis”. How did life then venture away from their supply of H2/electrons and colonize the rest of Earth? One lineage of life weaned itself off H2 through harnessing light energy and another lineage of life further refined H2 utilization, giving rise to the domain Bacteria equipped with “photosynthesis” and the domain Archaea with “methanogenesis”. Later, H2 mediated the merger between Bacteria and Archaea, yielding the third domain of life with complex cells – Eukarya. 

Dr. Chris House

"Hydrogen Impacts on Isotopic Fractionations by Microorganisms"

Isotopes are fractionation during chemical processes leading to a high number of biogeochemical isotopic tracers in the natural world. Most prominent of these useful systems are carbon isotopes, where the carbon isotopic compositions of materials can provide useful constraints on the carbon cycle, reveal the origin of carbon-containing gases like methane, demonstrate the operation of novel or cryptic metabolisms, or provide the part of possible life detection investigations of other worlds. Methanogenensis (the biological production of methane) is an important process for which carbon isotopic fractionation is well-studied. It has, however, only been recently recognized that the carbon isotopic fractionation from carbon dioxide to methane is largely influenced by the availability of hydrogen. In this talk, we will explore carbon isotopes, look at carbon isotopic fractionation by microorganisms on Earth, and discuss how and why hydrogen isotopes are critical to the magnitude of fractionation observed in methanogenesis and methanotrophy.

Dr. William Leavitt

"What Environment Information Do Archaeal Lipids Encode In Their Hydrogen Isotope Compositions?"

Life has three major groups – eukarya, bacteria, and archaea. This story focuses on the often overlooked archaea. Archaea are microbes critical to the cycling of matter and energy on Earth. They have played this important role throughout the history of the planet. Like all life on Earth, archaea are made up of elements such as carbon, oxygen and hydrogen. These elements form larger organic molecules that are required by all life such as DNA, proteins, and lipids. Geobiologists study these organic molecules to learn about life on Earth today and in the past. However, not all of these are preserved over long periods of time. Most DNA and proteins break down quickly and can only be used to study Earth today. Lipids are often much hardier and so are useful to geobiologists because they can be preserved in rocks for millennia. Lipids from archaea are particularly hardy and do not break down easily. This means that they can store information about the place in which the microbe lived. Long after they die, the lipids made by archaea can be extracted from muds, oils, and rocks. Geobiologists examine the structures and atoms of these lipids built by archaea millions of years ago to learn about Earth's past. However, it is not easy to decode the information in the lipids of long dead microbes correctly. To do this well, it is important to study these same lipids in modern systems and in the lab. This project will study several important archaea in the lab and shed light on how the different kinds of hydrogen atoms are used by archaea to build their lipids. The results will lead to advances in interpreting what lipids from archaea can tell us about the places they lived recently, and millions of years in the past.

Dr. Alexis Templeton

"Dynamics of Hydrogen Production and Consumption in Ultramafic Rock Aquifers"

Iron-rich ultramafic rocks are unstable in the presence of water and will react to produce hydrogen at variable rates, depending upon the temperature, rock composition and fluid flux.  In many subsurface systems experiencing fluid circulation, the hydrogen production that occurs is intimately associated with in-situ microbial consumption, sustaining an active microbial biosphere.  I’ll share new insights into the controls on hydrogen production from water/rock reactions, and how dynamically the subsurface microbial community can respond to changes in the hydrogen flux, depending upon how extreme the challenges of energy and carbon limitation may be.  Such data has important implications for life detection on Earth and other planetary bodies, as well as new efforts to engineer geological systems to extract hydrogen as a future clean energy resource.

Dr. Barbara Sherwood Lollar

"Competition for Natural Hydrogen - The Shake-Down Between the Deep Microbial Biosphere and the Green Energy Transition"

The challenges of the green energy transition to address the ever-increasing effects of climate change has raised the profile of naturally-occurring geologic hydrogen accumulations in the crust – but the foundational research on this phenomenon arose from investigations focused on life forms other than humans. Scientists investigating microbial communities identified water-rock chemical reactions such as serpentinization and radiolysis that produce critical electron donors (e.g. hydrogen) and electron acceptors (e.g. sulfate) capable of sustaining chemolithotrophic microbial communities in the oceanic and terrestrial crust. Insights from terrestrial analog sites suggest new potential models for planetary habitability capable of sustaining chemolithotrophic life on planets where photosynthesis may never have arisen, and have catalysed an expanded search for habitable environments on planets, exoplanets and moons to include not only surface based life but potentially vast subsurface biospheres. 

Dr. Douglas Wicks

"GeoH2 for Energy - Will This Starve the Subsurface Microbiome?"

The presentation will focus on the potential of geologic sources of hydrogen to be a new primary energy source and who this could play a major role in the transition away from hydrocarbons.  Key questions to be addressed within the talk are:

-       How does hydrogen factor into the energy transition?

-       What are the technical challenges to be addressed in harnessing this resource?

-       How does ARPA-E see the opportunity developing?

-       Why is the speaker coming to talk at a geobiology symposium?

Dr. Bradley Burcar

"Explore NASA Astrobiology: Demystifying the Proposal Process

Everything about the funding process through NASA is often confusing and intimidating, especially when early career scientists first start to seek out their own independent sources of funding. This presentation aims to simplify the steps involved in applying for funding and participating in NASA's astrobiology programs. Learn how to make your proposals relevant to current scientific goals, gain an overview of major funding programs, and understand how the review panel process works. Additionally, the presentation will highlight specific opportunities available to early career researchers, focusing not only on important steps for your next career stage, but what opportunities are relevant to you right now, including how to personally get involved in review panels to see for yourself how the review process works.