Award: OCE-1558483

We previously isolated and sequenced the genomes of the first cultured representatives from a lineage of marine bacteria that dominate marine oxygen minimum zones (SUP05). Support from this project used comparative genomics, proteomics, transcriptomics, and cryo-electron microscopy to characterize the diverse roles of these autotrophic and heterotrophic bacteria in marine carbon, nitrogen, and sulfur cycling (Fig. 1). Information from our cultures was also used to inform field studies that demonstrated significant carbon fixation rates by chemoautotrophic bacteria in the deep ocean and the importance of low oxygen concentrations in determining the magnitude of chemoautotrophic carbon fixation by SUP05. While investigating the roles of these bacteria in marine nutrient cycles, we also discovered viruses that infect and recombine DNA in the ocean's most abundant lineage of bacteria, SAR11 (Fig. 2). Through these research efforts, we produced several important publications that constitute the bulk of Dr. Speitz's Ph.D., which she successfully defended in Nov. 2017, and two chapters of Dr. Shah's Ph.D. thesis, which she successfully defended on Jan. 2018. This project also supported an undergraduate researcher (Ms. Kelsy Cain), who isolated the first strain of SAR11 with a virus in its genome. Dr. Spietz, Dr. Shah, and PI R. Morris have presented research highlighting many of these key findings at national and international meetings, at other academic institutions, and at national laboratories and Ms. Cain presented this work in a public setting as part of her honors thesis. All published data associated with this project is publicly available through natioinal data arhives and through the Biological and Chemical Oceanography Data Management Office (BCO-DMO). Last Modified: 02/05/2021 Submitted by: Robert Morris