Stable isotopic signature of dissimilatory nitrate reduction is robust against enzyme mutation.

ABSTRACT: The proportionality of oxygen-to-nitrogen isotope effects (¹⁸ε/¹⁵ε) is used as a key isotopic signature of nitrogen cycling processes in the environment. Dissimilatory nitrate reduction is observed to have an ¹⁸ε/¹⁵ε proportionality of ~0.9 in marine and ~0.6 in freshwater/terrestrial ecosystems. The origins of this difference are uncertain, with both geochemical and biological factors conceivably at play. One potential factor is variation in the isotope effect of nitrate reduction among different forms of the nitrate reductase enzyme. NarG nitrate reductases are observed to typically have an ¹⁸ε/¹⁵ε of ~0.9. However, a recent study uncovered an exception, with Bacillus NarG enzymes having an ¹⁸ε/¹⁵

SUBMITTER: Asamoto CK 

PROVIDER: S-EPMC11621745 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature