Revealing Keystone Arctic microbial genomes

• Main Authors: Royo-Llonch, Marta, Sánchez, Pablo, Pedrós-Alió, Carlos, Tara Oceans Consortium, Acinas, Silvia G.
• Format: Conference Object
• Language: unknown
• Published: Scientific Committee on Antarctic Research 2018
• Subjects: Arctic; Microbial genomes; Metagenomics; MAGs; Tara Oceans; Antarctic; Arctic Ocean; North Pole; Antarc*; Phytoplankton; SCAR; Scientific Committee on Antarctic Research
• Online Access: http://hdl.handle.net/10261/193261

IX Simposio de Estudios Polares del Comité Español del Scientific Committee on Antarctic Research (SCAR), 5-7 September 2018, Madrid, España.-- 1 page Microbial community composition in the North Polar waters varies greatly throughout the year. From what it is known so far, spring melting of the ice and increase in light disposal spur the bloom of phytoplankton. During summer, bacterial populations, mainly heterotrophic and photoheterotrophic, feed on the nutrients derived from such bloom. With fall’s shorter light hours and colder seawater temperatures, the bacterial community shifts towards chemolithoautotrophic microorganisms, that will prevail during winter. In 2013 Tara Oceans navigated Arctic waters during spring, summer and the beginning of fall (May to October), extensively sampling the microbial plankton communities. Here, we show the reconstruction of 2555 bacterial and archaeal metagenomic assembled genomes (MAGs) from 41 microbial metagenomes, covering the whole Arctic Ocean from spring to early fall at different water depths. Together with the physicochemical information of all stations we are capable of linking habitat preferences (generalistsvs specialist) of the different prokaryotic taxa around the North Pole with seasonality and the phenology of phytoplankton blooms at the maximum resolution possible, the genome level. Of the reconstructed prokaryotic MAGs, 96 are considered to be high-quality draft-like genomes (>90% genome completeness, <5% contamination), comprising keystone genomes and several potential new phyla, including unexpected taxa such as Dehaloccocoidetes, a group that had never been described in polar oceans waters. Analyses of the functional capacity of prokaryotic MAGs across their phylogeny allows disentangling the prevalence of convergent versus divergent evolution processes in prokaryotic species. Moreover, the metabolic capacity of these uncultured prokaryotic genomes reveals the ubiquity of chemolithoautotrophic metabolisms in this environment through the different ...