Current Research Projects
Mechanisms of carbon assimilation and sulfur oxidation in the genus Thioglobus
We now have in pure culture the only known isolates from an important group of marine sulfur oxidizers and are adressing fundamental questions about their roles in carbon and sulfur cycling. Our data indicate that they use energy derived from aerobic sulfur oxidation to assimilate carbon. This suggests that sulfur oxidation enhances carbon turnover in the oxygenated ocean. We will continue to elucidate the important roles of this ubiquitous and abundant group of organisms in marine carbon and sulfur cycles.
Characterizing biological function across a persistent oceanographic "hotspot"
Here we use post-genomic approaches to probe the activities of cells across an ocean boundary that extends into a high nutrient low chlorophyll (HNLC) region in the North Pacific. We use metagenome and metatrascriptome, protein expression, metabolite profiles and cell-specific metal quotas to identify feedbacks and functional linkages between biological communities and their geochemical surroundings.
Establishing a UW Marine Bacterial Culture Collection
Here we use filter-sterilized seawater media amended with natural sources of organic matter to increase the number and diversity of bacteria obtained by high throughput cultivation. We have isolated the first cultured representative from the gamma-sulfur oxidizer (GSO) clade (Marshall and Morris, in press), and have obtained additional cultures from the OM43, OMG, SAR116, and SAR11 clades.
Past Research Projects
Proteomics Directed Environmental Genomics
Here we used proteomic approaches to identify the in situ functions of bacterial communities in the South Atlantic Ocean. We identified shifts in bacterial nutrient utilization and energy transduction accross the South Atlantic and resolved unique patterns in community structure along basin-scale gradients in nutrients, chlorophyll, and dissolved organic carbon (Morris et al., 2010, Morris et al., 2012).