Functional Genomic Investigations of Iron and Carbon Cycle Coupling in Select Keystone Marine Bacteria Heterotrophs

Chris Dupont, PhD and collaborator Katherine Barbeau, PhD, from the Scripps Institute of Oceanography, intend to use transcriptomics and genome engineering to investigate the iron and carbon metabolism of the marine bacteria, Alteromonas.

Thriving in nutrient rich environments, Alteronomas can be found in both open and coastal waters. Scientists believe they play an oversized role in the iron and carbon cycles in our oceans and consider them to be a keystone species in marine ecosystems.

As heterotrophic microorganisms, Alteronomas rely on organic carbon as their food source, as they are unable to produce food on their own. Because of this, they are responsible for breaking down much of the dissolved organic matter in our oceans, regulating the regeneration cycles of nutrients that other species largely depend upon for their survival.

Past research was conducted under iron and carbon limiting conditions to identify what parts of Alteromonas’ genome are responsive to these constraints. With this new grant, Drs. Dupont and Bardeau plan to develop new molecular tools in order to manipulate or remove the responsive gene clusters, effectively editing the genome, so they can observe the resulting phenotype. The research will develop needed molecular tools for the commiunity and elucidate metabolic processes that make Alteromanas such a major player in our marine ecosystems. The team will also provide a new genome-engineering toolkit for Altermonas to share with the greater marine microbial community.

Additional post doctoral research is being done to show the utility of making engineered strains to “bioreport” what is happening from the microbial perspective.