Oxidation state of bioavailable dissolved organic matter influences bacterioplankton respiration and growth efficiency.

ABSTRACT: Oxygen consumption by oceanic microbes can predict respiration (CO₂ production) but requires an assumed respiratory quotient (RQ; ΔO₂/ΔCO₂). Measured apparent RQs (ARQs) can be impacted by various processes, including nitrification and changes in dissolved organic matter (DOM) composition, leading to discrepancies between ARQ and actual RQ. In DOM remineralization experiments conducted in the eastern North Atlantic Ocean, ARQs averaged 1.39 ± 0.14, similar to predictions for complete consumption of plankton biomass. DOM removed with an elevated nominal oxidation state (i.e., more oxidized DOM), as detected by liquid chromatography-tandem mass spectrometry, coincided with increased hydrolyzable amino acid removal, increased ARQs and bacterioplankton respirat

SUBMITTER: Stephens BM 

PROVIDER: S-EPMC11779884 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature