Geochemical transition zone powering microbial growth in subsurface sediments

Proceedings of the National Academy of Sciences, vol. 117, pp. 32617–32626

Abstract

Significance The marine sedimentary subsurface is a vast and inhospitable ecosystem, often described as a place where microbes “race to their death,” as microbial cells are buried and available energy is severely diminished with increasing depth/age. By combining a variety of biogeochemical and molecular methods to describe the energetics and genetics of the bacteria specialized in anaerobic ammonium oxidation, we show that despite prolonged exposure to highly unfavorable conditions for tens of thousands of years, these bacteria exhibit remarkable net population growth when reaching their niche: the nitrate–ammonium transition zone. This common, yet understudied, geochemical transition zone represents an oasis in the sedimentary energetic desert, and the growth it supports is of major importance for the global nitrogen cycle.

Authors 8

1. Rui Zhao corresponding

   University of Bergen · University of Delaware

   Affiliation as printed

   K.G. Jebsen Centre for Deep Sea Research, University of Bergen, 5007 Bergen, Norway;

   School of Marine Science and Policy, University of Delaware, Lewes, DE 19958;

2. José Manuel Mogollón Aachen Institute of Environmental Sciences (CML)

   Leiden University

   Affiliation as printed

   Institute of Environmental Sciences (CML), Leiden University, 2333 CC Leiden, The Netherlands;

3. Sophie S. Abby

   University of Vienna

   Affiliation as printed

   Division of Archaea Biology and Ecogenomics, Department of Functional and Evolutionary Ecology, University of Vienna, A-1090 Vienna, Austria

4. Christa Schleper

   University of Vienna

   Affiliation as printed

   Division of Archaea Biology and Ecogenomics, Department of Functional and Evolutionary Ecology, University of Vienna, A-1090 Vienna, Austria

5. Jennifer F. Biddle

   University of Delaware

   Affiliation as printed

   School of Marine Science and Policy, University of Delaware, Lewes, DE 19958;

6. Desiree L. Roerdink

   University of Bergen

   Affiliation as printed

   K.G. Jebsen Centre for Deep Sea Research, University of Bergen, 5007 Bergen, Norway;

7. Ingunn H. Thorseth

   University of Bergen

   Affiliation as printed

   K.G. Jebsen Centre for Deep Sea Research, University of Bergen, 5007 Bergen, Norway;

8. Steffen L. Jørgensen corresponding

   University of Bergen

   Affiliation as printed

   K.G. Jebsen Centre for Deep Sea Research, University of Bergen, 5007 Bergen, Norway;