Potential cobalt limitation of vitamin B12 synthesis in the North Atlantic Ocean

• Published in: Global Biogeochemical Cycles
• Main Authors: Panzeca, C., Beck, A., Leblanc, Karine, Taylor, G.T., Hutchins, D.A., Sanudo-Wilhelmy, Sergio
• Other Authors: School of Marine and Atmospheric Sciences Stony Brook (SoMAS), Stony Brook University SUNY (SBU), State University of New York (SUNY)-State University of New York (SUNY), Laboratoire d'océanographie et de biogéochimie (LOB), Université de la Méditerranée - Aix-Marseille 2-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Biological Sciences Los Angeles, University of Southern California (USC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; North Atlantic
• Online Access: https://hal.archives-ouvertes.fr/hal-00702673; https://hal.archives-ouvertes.fr/hal-00702673/document; https://hal.archives-ouvertes.fr/hal-00702673/file/2007GB003124.pdf; https://doi.org/10.1029/2007GB003124

While recent studies have confirmed the ecological importance of vitamin B12, it is unclear whether the production of this vitamin could be limited by dissolved Co, a trace metal required for B12 biosynthesis, but found at only subnanomolar concentrations in the open ocean. Herein, we demonstrate that the spatial distribution of dissolved B12 (range: 0.13-5 pmol L−1) in the North Atlantic Ocean follows the abundance of total dissolved Co (range: 15-81 pmol L−1). Similar patterns were observed for bacterial productivity (range: 20-103 pmol 3H leucine L−1 hr−1) and algal biomass (range: 0.4-3.9 μg L−1). In contrast, vitamin B1 concentrations (range: 0.7-30 pM) were decoupled from both Co and B12 concentrations. Cobalt amendment experiments carried out in low-dissolved Co waters (∼20 pmol L−1) enhanced B12 production two-fold over unamended controls. This study provides evidence that B12 synthesis could be limited by the availability of Co in some regions of the world ocean.