Investigation of the presence and role of poly-phosphate accumulating microorganism (PAOs) in phosphorus cycle and utilization in lake and sediment

April Gu and the Gu lab in Civil Engineering at Cornell.

A better understanding of the P cycling in natural environments is of great significance for global P management. Although it is ultimately important to consider the full spectrum of all P compounds, polyphosphate (PolyP) is an overlooked but significant mediator of global P cycling. Based on a published large-scope survey among 22 European lakes differing in trophic status, biogeochemistry, hydrology, and morphology, NMR analysis showed PolyP/TP ratios in surface sediments varied from 1.5 to 11.4%. In all cases where PolyP was detected, it was regarded to be biotically generated. The settlement of PolyP-containing microorganisms onto sediments could also serve as an input for sediment PolyP. In the summers of 2019 and 2020 we documented PolyP in sediments of Oneida Lake using NMR, polyP staining, and single cell Raman microspectroscopy. A former intern on this project is now a PhD student with Dr. Gu (Matthew Baldwin). Primary activities in 2022 was analysis and manuscript preparation.