Production of siderophore type chelates in Atlantic Ocean waters enriched with different carbon and nitrogen sources

• Published in: Marine Chemistry
• Main Authors: Mawji, Edward, Gledhill, M., Milton, J.A., Zubkov, M.V., Thompson, Anu, Wolff, George A., Achterberg, Eric P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: North Atlantic
• Online Access: https://eprints.soton.ac.uk/170213/; https://eprints.soton.ac.uk/170213/1/Mawji_et_al_Marine_Chemistry_revised.pdf

Siderophore type chelates were detected in nutrient enriched, incubated seawater collected from different biogeographical regions of the Atlantic Ocean. Seawater was enriched with glucose and ammonium, glycine (as a source of carbon and nitrogen) or chitin and ammonium at different concentrations and incubated for up to 3 – 4 days in the dark. Siderophore type chelates were detected using high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) after complexation with Ga. Samples were subsequently analysed by HPLC - electrospray ionisation mass spectrometry (HPLC ESI-MS) in order to confirm the identity of the known siderophores, and to obtain the pseudo molecular ions of unknown siderophore type chelates. A total of 22 different siderophore type chelates were resolved in the HPLC-ICP-MS chromatograms. Ten different siderophore type chelates were identified by HPLC-ESI-MS, 3 of which had not previously been identified in nutrient enriched seawater incubations. The concentration and diversity of siderophore typechelates was highest in seawater amended with glucose. The concentrations 1 and diversity of siderophore type chelates also varied with biogeographical area in the Atlantic Ocean, with the North Atlantic Sub-tropical Gyre yielding highest concentrations in incubations, and the South Atlantic Sub-tropical Gyre and Western Tropical Atlantic yielding the highest diversity.