Constraining biorecalcitrance of carboxyl-rich alicyclic molecules in the ocean.

ABSTRACT: Marine dissolved organic matter (DOM) is one of Earth's largest long-term carbon reservoirs, critical to the global carbon cycle. A key breakthrough in understanding this pool is the identification of biorefractory carboxyl-rich alicyclic molecules (CRAM). Recent studies have challenged the biorecalcitrance of CRAM but lacked detailed molecular evidence. Using advanced online countergradient liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry to track microbial incubation, we revealed a wide spectrum of CRAM bioavailability regulated by molecular polarity. CRAM with lower polarity were preferentially degraded, whereas microbial reworking led to production of higher-polarity CRAM, characterized by increased oxidation state, nitrogen content, and aromaticity. So

SUBMITTER: Cai R 

PROVIDER: S-EPMC12248312 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature