A mosaic of metabolic traits underlie the divergence of SAR11 ecotypes

Come chat: Thursday 16:30 to 17:30 (Poster Number: PS3.15.100)

Sarah J. Tucker ^1,2,3,4, Kelle C. Freel ¹, A. Murat Eren^2,3,4,5,6, Michael S. Rappé¹

¹ Hawaiʻi Institute of Marine Biology, University of Hawaiʻi at Mānoa, Kāneʻohe, United States; ² Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, United States; ³ Helmholtz Institute for Functional Marine Biodiversity, Oldenburg, Germany; ⁴ Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; ⁵ Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany; ⁶Max Planck Institute for Marine Microbiology, Bremen, Germany; *Correspondence: stucker@mbl.edu, rappe@hawaii.edu

Abstract: The Order Pelagibacterales (SAR11) is the most abundant group of heterotrophic bacteria in the global surface ocean and a critical participant in oceanic biogeochemical cycles. SAR11 forms multiple major and minor subclades that exhibit unique spatiotemporal distributions and contain extensive genetic and ecological diversity. Yet, due to incredibly high genetic diversity and a limited number of representatives available in laboratory culture, understanding the determinants of niche partitioning within SAR11 has been a formidable challenge. Here, we took advantage of 71 new SAR11 genomes from strains isolated from the tropical Pacific Ocean to evaluate the distribution of metabolic traits across SAR11 subclades. We also used this expanded collection of SAR11 genomes to recruit reads from metagenomes collected from the environment where the strains were isolated. This approach revealed distinct habitat preferences across SAR11 subclades for coastal or offshore environments, and the accumulation of differences in metabolic traits that likely support these habitat preferences, predominantly involved in the metabolism of organic carbon and the acquisition of nitrogen from organic sources. Habitat preferences and metabolic traits were distributed polyphyletically across SAR11 subclades, suggesting that they were not derived from a single common ancestor, but instead emerged across multiple lineages independently. Together these insights reveal niche-partitioning within sympatric and parapatric populations of SAR11 and demonstrate that the immense genomic diversity of SAR11 subclades naturally segregates into ecologically and genetically cohesive units, or ecotypes, that vary in spatial distributions in the tropical Pacific.

Other co-authored presentations:

Diverse new isolate genomes help to elucidate fundamental ecologically-relevant units of SAR11 marine bacteria

Visit the poster: Monday

Kelle C. Freel ¹, Sarah J. Tucker ^1,2,3,4, Evan B. Freel¹, A. Murat Eren^2,3,4,5,6, Michael S. Rappé¹

¹ Hawaiʻi Institute of Marine Biology, University of Hawaiʻi at Mānoa, Kāneʻohe, United States; ² Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, United States; ³ Helmholtz Institute for Functional Marine Biodiversity, Oldenburg, Germany; ⁴ Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; ⁵ Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany; ⁶Max Planck Institute for Marine Microbiology, Bremen, Germany; *Correspondence: kfreel@hawaii.edu, rappe@hawaii.edu

Isolate-anchored comparisons reveal evolutionary and functional differentiation across SAR86 marine bacteria

Visit the poster: Monday

Kelle C. Freel ¹, Oscar Ramfelt^1,2, Sarah J. Tucker ^1,3, Olivia D. Nigro⁴, Michael S. Rappé¹

¹ Hawaiʻi Institute of Marine Biology, University of Hawaiʻi at Mānoa, Kāneʻohe, United States; ² Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, Honolulu, United States; ³ Marine Biology Graduate Program, University of Hawaiʻi at Mānoa, Honolulu, United States; ⁴ Department of Natural Science, Hawaiʻi Pacific University, Honolulu, United States; *Correspondence: rappe@hawaii.edu

Leveling up pangenomics with pangenome graphs

Visit the poster: Tuesday

Alexander Henoch^1,2,*, Sarah J. Tucker^1,2,3, Metehan Sever^1,2, Iva Veseli^1,2, Florian Trigodet^1,2, Arda Söylev^4,5, Kelle C. Freel⁶, Michael S. Rappé⁶, A. Murat Eren^1,2,3,7,8,*

¹Helmholtz Institute for Functional Marine Biodiversity, 26129 Oldenburg, Germany; ²Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570 Bremerhaven, Germany; ³Marine Biological Laboratory, Woods Hole, MA 02543, USA; ⁴Institute for Medical Biometry and Bioinformatics, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; ⁵Center for Digital Medicine, Heinrich Heine University, 40225 Düsseldorf, Germany; ⁶Hawai’i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai’i at Mānoa, Kāne’ohe, HI 96744, USA; ⁷Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, 26129 Oldenburg, Germany; ⁸Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany; *Correspondence: alexander.henoch@hifmb.de, meren@hifmb.de

Succession of the Yellow Tang (Zebrasoma flavescens) Microbiome From Hatch to Settlement in a Recirculating Aquaculture System

Visit the poster: Thursday

Annie Deck¹, Sarah Tucker², Matthew Iacchei¹, Chatham Callan¹, Michael Rappé², Olivia Nigro¹

¹ Department of Natural and Computational Sciences, Oceanic Institute, Hawaiʻi Pacific University, ² Hawaiʻi Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawaiʻi at Mānoa; *Correspondence: adeck@hawaii.edu, onigro@hpu.edu