Minimal cobalt metabolism in the marine cyanobacterium Prochlorococcus.

Hawco, Nicholas J, McIlvin, Matthew M, Bundy, Randelle M, Tagliabue, Alessandro ORCID: 0000-0002-3572-3634, Goepfert, Tyler J, Moran, Dawn M, Valentin-Alvarado, Luis, DiTullio, Giacomo R and Saito, Mak A (2020) Minimal cobalt metabolism in the marine cyanobacterium Prochlorococcus. Proceedings of the National Academy of Sciences of the United States of America, 117 (27). pp. 15740-15747.

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Official URL: https://www.pnas.org/content/117/27/15740

Abstract

Despite very low concentrations of cobalt in marine waters, cyanobacteria in the genus Prochlorococcus retain the genetic machinery for the synthesis and use of cobalt-bearing cofactors (cobalamins) in their genomes. We explore cobalt metabolism in a Prochlorococcus isolate from the equatorial Pacific Ocean (strain MIT9215) through a series of growth experiments under iron- and cobalt-limiting conditions. Metal uptake rates, quantitative proteomic measurements of cobalamin-dependent enzymes, and theoretical calculations all indicate that Prochlorococcus MIT9215 can sustain growth with less than 50 cobalt atoms per cell, ∼100-fold lower than minimum iron requirements for these cells (∼5,100 atoms per cell). Quantitative descriptions of Prochlorococcus cobalt limitation are used to interpret the cobalt distribution in the equatorial Pacific Ocean, where surface concentrations are among the lowest measured globally but Prochlorococcus biomass is high. A low minimum cobalt quota ensures that other nutrients, notably iron, will be exhausted before cobalt can be fully depleted, helping to explain the persistence of cobalt-dependent metabolism in marine cyanobacteria.

Item Type:	Article
Uncontrolled Keywords:	Prochlorococcus, vitamin B12, iron, Pacific Ocean, nutrient limitation
Depositing User:	Symplectic Admin
Date Deposited:	18 Aug 2020 13:35
Last Modified:	18 Jan 2023 23:37
DOI:	10.1073/pnas.2001393117
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3098013