Copper limiting threshold in the terrestrial ammonia oxidizing archaeon Nitrososphaera viennensis

Author(s)
Carolina Reyes, Logan Hodgskiss, Oliver Baars, Melina Kerou, Barbara Bayer, Christa Schleper, Stephan Krämer
Abstract

Ammonia oxidizing archaea (AOA) inhabiting soils have a central role in the global nitrogen cycle. Copper (Cu) is central to many enzymes in AOA including ammonia monooxygenase (AMO), the enzyme involved in the first step of ammonia oxidation. This study explored the physiological response of the AOA soil isolate, Nitrososphaera viennensis (EN76T) to Cu-limiting conditions in order to approach its limiting threshold under laboratory conditions. The chelator TETA (1,4,8,11-tetraazacyclotetradecane N, N’, N’’, N’’’-tetraaceticacid hydrochloride hydrate) with selective affinity for Cu2+ was used to lower bioavailable Cu2+ in culture experiments as predicted by thermodynamic speciation calculations. Results show that N. viennensis is Cu-limited at concentrations ≤10-15 mol L-1 free Cu2+ compared to standard conditions (10-12 mol L-1). This Cu2+ limiting threshold is similar to pure cultures of denitrifying bacteria and other AOA and AOB inhabiting soils, freshwaters and sewage (<10-16 mol L-1), and lower than pure cultures of the marine AOA Nitrosopumilus maritimus (<10-12.7 mol L-1), which also possesses a high amount of Cu-dependent enzymes.

Organisation(s)
Department of Environmental Geosciences
External organisation(s)
North Carolina State University
Journal
Research in Microbiology
Volume
171
Pages
134-142
No. of pages
9
ISSN
0923-2508
DOI
https://doi.org/10.1016/j.resmic.2020.01.003
Publication date
09-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
106022 Microbiology, 105906 Environmental geosciences
Keywords
ASJC Scopus subject areas
Molecular Biology, Microbiology
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucris.univie.ac.at/portal/en/publications/copper-limiting-threshold-in-the-terrestrial-ammonia-oxidizing-archaeon-nitrososphaera-viennensis(a547e447-1bab-41fa-9594-398cf66612e5).html