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 (EN76^T) 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‴-tetraacetic acid 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.

居住在土壤中的氨氧化古细菌（AOA）在全球氮循环中起着核心作用。铜（Cu）是AOA中许多酶的核心，包括氨单加氧酶（AMO），该酶参与氨氧化的第一步。这项研究探索了AOA土壤分离物，Nitrososphaera viennensis（EN76 ^T）对铜限制条件的生理响应，以便在实验室条件下达到其限制极限。螯合剂TETA（1,4,8,11-四氮杂环十四烷N，N'，N''，N‴-四乙酸盐酸盐水合物）具有选择性的对Cu ^2+的亲和力，用于降低培养实验中的生物利用度Cu ²⁺热力学形态计算。结果表明与标准条件（10 ^-12  mol L ^-1）相比，维也纳猪笼草的铜含量受限于≤10 ^-15  mol L ^-1的游离Cu ²⁺。该Cu ²⁺极限阈值类似于反硝化细菌和其他居住在土壤，淡水和污水中的AOA和AOB的纯培养物（<10 ^-16  mol L ^-1），并且低于海洋AOA的Nitrosopumilus maritimus的纯培养物（<10 ^-12.7  mol L ^-1），也具有大量的Cu依赖酶。