bioRxiv preprint doi: https://doi.org/10.1101/814418; this version posted October 22, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Genome diversification in globally distributed novel 2 marine Proteobacteria is linked to environmental adaptation 3 4 Authors: Zhichao Zhou1, Patricia Q. Tran1, 2, Kristopher Kieft1, Karthik Anantharaman1* 5 6 7 Affiliations: 8 1Department of Bacteriology, University of Wisconsin–Madison, Madison, WI, 53706, USA 9 2Department of Integrative Biology, University of Wisconsin–Madison, Madison, WI 53706, 10 USA 11 12 13 *Corresponding author 14 Email:
[email protected] 15 Address: 4550 Microbial Sciences Building, 1550 Linden Dr., Madison, WI, 53706 16 17 Abstract 18 Proteobacteria constitute the most diverse and abundant group of microbes on Earth. In 19 productive marine environments like deep-sea hydrothermal systems, Proteobacteria have been 20 implicated in autotrophy coupled to sulfur, methane, and hydrogen oxidation, sulfate reduction, 21 and denitrification. Beyond chemoautotrophy, little is known about the ecological significance 22 of novel Proteobacteria that are globally distributed and active in hydrothermal systems. Here 23 we apply multi-omics to characterize 51 metagenome-assembled genomes from three 24 hydrothermal vent plumes in the Pacific and Atlantic Oceans that are affiliated with nine novel 25 Proteobacteria lineages. Metabolic analyses revealed these organisms to contain a diverse 26 functional repertoire including chemolithotrophic ability to utilize sulfur and C1 compounds, 27 and chemoorganotrophic ability to utilize environment-derived fatty acids, aromatics, 28 carbohydrates, and peptides.