Marine phytoplankton produce half of all fixed carbon on the planet, making a significant fraction available for microbial communities to utilize. This pivotal link between primary producers and heterotrophic bacteria is critical in the transformation of dissolved organic matter (DOM) in the ocean. Abiotic factors such as temperature can play an important role in governing the rate at which DOM is processed by microbial communities. However, the ways in which changing temperature will influence the production and consumption of DOM remains unknown. The impact of an altered temperature regime on the endometabolome composition of temperature-acclimated strains of the marine diatom Thalassiosira pseudonana was determined by LC-MS analysis. These data indicate higher concentrations of nucleic acid building blocks (e.g. hypoxanthine, uracil) and organic acids (e.g. 4-pyridoxic acid, 3-hydroxyanthranilic acid) at the warmest temperature (28°C), and of proline, 5’-methylthioadenosine, and abscisic acid at the coolest temperature (14°C). DOM consisting of endo- and exometabolite pools from the diatom strain was provided to a natural bacterial community, and uptake was tracked using gene expression as a proxy. Concurrent responses to altered temperature regimes by phytoplankton and their associated bacteria provide an important perspective on microbial processes in the future ocean.

Primary Presenter: McKenzie Powers, University of Georgia (mckpwrs@uga.edu)

Authors:

McKenzie Powers, University of Georgia  (mckpwrs@uga.edu)

Malin Olofsson, Swedish University of Agricultural Sciences  (malin.olofsson@slu.se)

Mario Uchimiya, University of Georgia  (mario.uchimiya@uga.edu)

Arthur Edison, University of Georgia  (aedison@uga.edu)

Brian Hopkinson, University of Georgia  (bmhopkin@uga.edu)

Mary Ann Moran, University of Georgia  (mmoran@uga.edu)