Linking diagenetic alteration of amino acids and bulk organic matter reactivity

Examination of amino acids in particulate samples from a variety of marine environments (fresh phytoplankton to deep‐sea sediments) revealed systematic compositional changes upon progressive degradation. These consistent trends have been used to derive a quantitative degradation index (DI) that is directly related to the reactivity of the organic material, as indicated by its lability to enzymatic decay and its first‐order degradation rate constant. This direct link between molecular composition and degradation rate allows us to quantify the quality of organic matter based solely on its chemical composition.