PT  - JOURNAL ARTICLE
AU  - Fernando Puente-Sánchez
AU  - Luis Macías
AU  - Karley L. Campbell
AU  - Marta Royo
AU  - Vanessa Balagué
AU  - Pablo Sánchez
AU  - Javier Tamames
AU  - C.J. Mundy
AU  - Carlos Pedrós-Alió
TI  - Bacterioplankton taxa compete for iron along the early spring-summer transition in the Arctic Ocean
AID  - 10.1101/2022.02.07.479392
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.02.07.479392
4099  - http://biorxiv.org/content/early/2022/02/10/2022.02.07.479392.short
4100  - http://biorxiv.org/content/early/2022/02/10/2022.02.07.479392.full
AB  - Microbial assemblages under sea ice of Dease Strait, Canadian Arctic, were sequenced for metagenomes and metatranscriptomes of the small size fraction (0.2 to 3 µm). The community from early March was typical for this season, with Alpha- and Gammaproteobacteria as the dominant taxa, followed by Thaumarchaeota and Bacteroidetes. Towards summer, Bacteroidetes and particularly the genus Polaribacter, became increasingly dominant, followed by the Gammaproteobacteria. Analysis of genes responsible for microbial acquisition of iron showed an abundance of ABC transporters for divalent cations and ferrous iron. The most abundant transporters, however, were the outer membrane TonB dependent transporters of iron-siderophore complexes. The abundance of iron acquisition genes suggested this element was essential for the microbial assemblage. Interestingly, Gammaproteobacteria were responsible for most of the siderophore synthesis genes. On the contrary, Bacteroidetes did not synthesize siderophores but accounted for most of the transporters, suggesting a role as cheaters in the competition for siderophores as public goods. Likely, this cheating ability of the Bacteroidetes contributed to their dominance in summer.Competing Interest StatementThe authors have declared no competing interest.