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2014 Annual Science Report

VPL at University of Washington Reporting  |  SEP 2013 – DEC 2014

Biogenic Gases From Anoxygenic Photosynthesis in Microbial Mats

Project Summary

This lab and field project aims to measure biogenic gas fluxes in engineered and natural microbial mats composed of anoxygenic phototrophs and anaerobic chemotrophs, such as may have existed on the early Earth prior to the advent of oxygenic photosynthesis. The goal is to characterize the biogeochemical cycling of S, H, and C in an effort to constrain the sources and sinks of gaseous biosignatures that may be relevant to the detection of life in anoxic biospheres on habitable exoplanets.

4 Institutions
3 Teams
1 Publication
1 Field Site
Field Sites

Project Progress

Field measurements were initially scheduled for summer 2014 to measure biogenic gases produced by anoxygenic mats dominated by the green non-sulfur filamentous anoxygenic phototroph Chloroflexus. However, the Yellowstone Research Permit Office notified us in June 2014 that we would not be allowed to sample the green Chloroflexus mats at New Pit Spring at Mammoth due to safety concerns. As a result, we contacted senior researcher Richard Castenholz from the University of Oregon and he showed us safer green Chloroflexus mats to sample during a field trip in August 2014 (Fig. 1). A permit will be obtained for these new sites and the biogenic gas measurements will be performed during summer 2015. We also will measure biogenic gases in a rooftop lab greenhouse at NASA Ames Research Center in which microbial mats from Guerrero Negro, Mexico, have been maintained long-term. This greenhouse is in the process of being relocated.

Springs in the Mammoth area containing mats of green Chloroflexus. Biogenic gas measurements will be done here summer 2015.

    Niki Parenteau
    Project Investigator

    Tori Hoehler

    Nancy Kiang

    Objective 4.1
    Earth's early biosphere.

    Objective 5.2
    Co-evolution of microbial communities

    Objective 5.3
    Biochemical adaptation to extreme environments

    Objective 6.1
    Effects of environmental changes on microbial ecosystems

    Objective 6.2
    Adaptation and evolution of life beyond Earth

    Objective 7.2
    Biosignatures to be sought in nearby planetary systems