Siderophore screening in marine sponge extracts using LC-HRMS and an R-based metabolomics workflow.

Area of Science:

• Marine Biology
• Metabolomics
• Microbial Ecology

Background:

• Siderophores are vital microbial biomolecules for iron acquisition, influencing survival, pathogenicity, and ecology.
• Understanding siderophores in marine holobionts provides insights into microbial dynamics and potential therapeutics.

Purpose of the Study:

• To develop and apply a culture-independent, data-centric strategy for annotating siderophores from marine sponge bodies.
• To identify and characterize siderophores within three marine sponge species.

Main Methods:

• Utilized Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS).
• Employed a custom R-based analytical workflow (XCMS and MetaboAnnotation).
• Applied a rigorous validation pipeline including iron-adduct calculations and mass accuracy thresholds.

Main Results:

• Putatively annotated 59 siderophores across Dragmacidon reticulatum, Aplysina fulva, and Amphimedon viridis.
• Annotations reached Level 2 (putatively annotated compounds) per Metabolomics Standards Initiative guidelines.
• Identified specific siderophores like Ferricrocin, Aeruginic acid, and Madurastatin within sponge bodies.

Conclusions:

• The developed workflow effectively bypasses cultivation limitations for siderophore discovery.
• Sponge-associated microbes constitutively produce or are saturated with siderophores, as iron supplementation did not alter detection.
• Revealed a diverse landscape of iron-chelating metabolites within marine sponges.