Collaborative Research: Dissolved phosphorus processing by Trichodesmium consortia: Quantitative partitioning, role of microbial coordination, and impact on nitrogen fixation

Lead PI: Sonya Dyhrman

Unit Affiliation: Biology and Paleo Environment, Lamont-Doherty Earth Observatory (LDEO)

October 2013 - September 2018
Atlantic Ocean ; Palisades, NY ; North Atlantic Ocean ; Woods Hole, MA
Project Type: Research

DESCRIPTION: Colonies of the cyanbacterium Trichodesmium are responsible for a large fraction of N2 fixation in nutrient-poor, open-ocean ecosystems, ultimately fueling primary production in both Trichodesmium and in the broader planktonic community. However, in some parts of the ocean, the scarcity of dissolved phosphorus limits rates of Trichodesmium N2 fixation. Trichodesmium colonies employ an arsenal of strategies to mitigate the effects of phosphorus limitation, and the consortia of epibiotic bacteria in the colonies may play a significant role in phosphorus acquisition.

In this study, researchers from Woods Hole Oceanographic Institution and Columbia University will use metagenomic and metatranscriptomic sequencing to investigate how phosphorus metabolism is coordinated in Trichodesmium consortia, and to discern the role of quorum sensing in phosphorus acquisition and partitioning. Results from this study are expected to expand understanding of Trichodesmium from a monospecific colony whose primary function is fixing CO2 and N2 toward a unique planktonic consortium with a diverse, complex, and highly coordinated overall metabolism that exerts profound control over the cycling of inorganic and organic nutrients in the oligotrophic upper ocean.

OUTCOMES: This project will provide research experience for an under-represented ethnic graduate student and take advantage of established K-12 standards-based outreach programs to increase ocean literacy in children and amongst the public.