Nitrogen Isotope Fractionation During Archaeal Ammonia Oxidation: Coupled Estimates From Measurements of Residual Ammonium and Accumulated Nitrite.

ABSTRACT: The naturally occurring nitrogen (N) isotopes, ¹⁵N and ¹⁴N, exhibit different reaction rates during many microbial N transformation processes, which results in N isotope fractionation. Such isotope effects are critical parameters for interpreting natural stable isotope abundances as proxies for biological process rates in the environment across scales. The kinetic isotope effect of ammonia oxidation (AO) to nitrite (NO₂ ^-), performed by ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), is generally ascribed to the enzyme ammonia monooxygenase (AMO), which catalyzes the first step in this process. However, the kinetic isotope effect of AMO, or ε _{A M O} , has been typically determined based on isot

SUBMITTER: Mooshammer M 

PROVIDER: S-EPMC7399158 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature