Hinrichs Lab - PAPAA

PAPAA: Plank­tonic ar­chaeal phos­phorus af­fin­ity and ap­por­tion­ment

Abstract

Travis Meador is leading a project that investigates nutrient recycling fluxes in oceanic surface waters by quantifying the phosphate affinity as well as the release of organic phosphorus by a model organism, Nitrosopumilus maritimus, a prolific planktonic archaeon.  N. maritimus plays a crucial role in the global nitrogen cycle, specializing in the conversion of recycled nitrogen (i.e., ammonia) to inorganic nitrite in order to generate energy, and in the global carbon cycle, assimilating inorganic carbon into biomass.

This study will assess the role of N. maritimus in the marine phosphorus cycle by (i) quantifying the uptake and partitioning of radiolabeled-P, and (ii) employing novel isolation and chemical characterization techniques to identify individual P-containing macromolecules. This information is essential for assessing factors that control  DOP biosynthesis and bioavailability, representing a caveat that has plagued previous microbiological and geochemical assessments of the spatial distribution and turnover of DOP that accumulates in aquatic environments.  In addition to these primary goals, combined results from this study will also provide estimates of cellular budgets and fluxes of carbon, nitrogen, and phosphorus in N. maritimus, which may occupy a distinct niche in the marine P cycle.