Orellana, M. University of Washington, Department of Bioengineering, morellan@u.washington.edu
Verdugo, P. University of Washington, Department of Bioengineering, verdugo@bioeng.washington.edu

Although a large pool of the organic carbon on earth is in the form of marine polymer gels, the polymer physics of these pool has received little attention. Marine polymer gels (MPG) range in size from large-scale (> cm) macrogels to submicron-scale (um-nm) colloidal gels. Macrogels result from microalgae exudate, particularly during phytoplankton blooms. Microgels are formed by fragmentation of macrogels, or they can also be spontaneously assembled from free-DOM polymers (Nature 391:568, 1998). The thermodynamics of assembly of free-DOM polymers into microgels has not been established. However, preliminary studies suggest that at equilibrium approximately 20% of DOM polymers can assemble into marine microgels (MMG), yielding an estimated DOM-derived microgel pool of about 3.4 x exp 17 gC. Here we will briefly focus on four important aspects of our research on MMG: mineralization, polymer gel phase transition, bacterial degradation, and the effect of UV radiation on NMG assembly. Mineralization and phase transition could provide an intriguing insight into carbon export (Nature, 391:530,1998); the role of MMG in bacterial grazing could have important implications in bacterial ecology; and the cracking of DOM-polymers by UV radiation can inhibit microgel assembly impacting carbon cycling and trophic dynamics.
Day: Monday, Feb. 1
Time: 02:00 - 02:15pm
Location: Sweeney Center
Code: SS17MO0200S