bioRxiv preprint doi: https://doi.org/10.1101/2021.07.22.453385; this version posted July 22, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Quantification of archaea‐driven freshwater nitrification: from 2 single cell to ecosystem level 3 4 5 Franziska Klotz1, Katharina Kitzinger2, David Kamanda Ngugi3, Petra Büsing3, Sten Littmann2, Marcel 6 M. M. Kuypers2, Bernhard Schink1, and Michael Pester1,3,4* 7 1. Department of Biology, University of Konstanz, Universitätsstrasse 10, Konstanz, D‐78457, Germany 8 2. Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D‐28359 Bremen, Germany. 9 3. Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, D‐38124 10 Braunschweig, Germany 11 4. Technical University of Braunschweig, Institute for Microbiology, Spielmannstrasse 7, D‐38106 12 Braunschweig, Germany 13 14 15 16 Short title: Archaeal nitrification in lakes 17 18 19 20 Keywords: freshwater lake | hypolimnion | nitrification | growth rate | cell‐specific rate | gene 21 transcription | AOA | ammonia oxidation 22 23 24 25 26 27 28 29 *Corresponding author: Michael Pester, Mail:
[email protected], Phone: +49 531 2616237 bioRxiv preprint doi: https://doi.org/10.1101/2021.07.22.453385; this version posted July 22, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Archaeal nitrification in lakes 30 Abstract 31 Deep oligotrophic lakes sustain large archaeal populations of the class Nitrososphaeria in their 32 hypolimnion.