Growth of complete ammonia oxidizers on guanidine

Marton Palatinszky, Craig W Herbold, Christopher J Sedlacek, Dominic Pühringer, Katharina Kitzinger, Andrew T Giguere, Kenneth Wasmund, Per H Nielsen, Morten K D Dueholm, Nico Jehmlich, Richard Gruseck, Anton Legin, Julius Kostan, Nesrete Krasnici, Claudia Schreiner, Johanna Palmetzhofer, Thilo Hofmann, Michael Zumstein, Kristina Djinović-Carugo, Holger DaimsMichael Wagner (Corresponding author)

Publications: Contribution to journalArticlePeer Reviewed

Abstract

Guanidine is a chemically stable nitrogen compound that is excreted in human urine and is widely used in manufacturing of plastics, as a flame retardant and as a component of propellants, and is well known as a protein denaturant in biochemistry1-3. Guanidine occurs widely in nature and is used by several microorganisms as a nitrogen source, but microorganisms growing on guanidine as the only substrate have not yet been identified. Here we show that the complete ammonia oxidizer (comammox) Nitrospira inopinata and probably most other comammox microorganisms can grow on guanidine as the sole source of energy, reductant and nitrogen. Proteomics, enzyme kinetics and the crystal structure of a N. inopinata guanidinase homologue demonstrated that it is a bona fide guanidinase. Incubation experiments with comammox-containing agricultural soil and wastewater treatment plant microbiomes suggested that guanidine serves as substrate for nitrification in the environment. The identification of guanidine as a growth substrate for comammox shows an unexpected niche of these globally important nitrifiers and offers opportunities for their isolation.

Original languageEnglish
Pages (from-to)646-653
Number of pages8
JournalNature
Volume633
Early online date14 Aug 2024
DOIs
Publication statusPublished - 19 Sep 2024

Austrian Fields of Science 2012

  • 105205 Climate change
  • 106026 Ecosystem research
  • 106022 Microbiology

Keywords

  • microbiology
  • Structural Biology
  • ammonia oxidizer
  • guanidine
  • comammox microorganisms
  • Complete Ammonia Oxidizer
  • Nitrospira inopinata

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