Program and Agenda

Abstract

MICROBIAL GROUP SPECIFIC UPTAKE OF INORGANIC PHOSPHATE AND ATP AT STATION ALOHA: KINETICS, EFFECT OF LIGHT AND RESPONSE TO RAPID CHANGES IN N:P AVAILABILITY

We used radiotracers to measure inorganic phosphate (Pi) and adenosine-5’-triphosphate (ATP) uptake into whole water communities, microbial size classes, and flow sorted groups; Prochlorococcus (PRO), Synechococcus (SYN) and non-pigmented bacteria (NPB), in the North Pacific Subtropical Gyre. We investigated the concentration dependent uptake of Pi and ATP in microbial populations. PRO and NPB were in close competition in terms of Pi acquisition, whereas P uptake from ATP could be attributed to NPB. Due to low abundances, SYN contributions to Pi and ATP uptake were negligible. PRO Pi and ATP uptake rates were higher when the samples were incubated under ambient light than in the dark, while there was no significant difference in assimilation by NPB between light and dark incubated samples. Following N-amendments, the system became P stressed (high alkaline phosphatase activity, increased P turnover rates), and SYN contribution to Pi and ATP uptake greatly increased to a comparable order of magnitude as NPB, suggesting that SYN could potentially be a key component of the P cycling when N limitation is relieved, particularly for organic P utilization.

ePoster:

Authors

Duhamel, S., Lamont-Doherty Earth Observatory, Columbia University, USA, sduhamel@ldeo.columbia.edu

Björkman, K. M., Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, USA, bjorkman@hawaii.edu

Doggett, J. K., Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, USA, doggett@hawaii.edu

Karl, D. M., Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, USA, dkarl@hawaii.edu

Details

Poster presentation

Session #:049
Date: 2/27/2014
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall

Presentation is given by student: No

PosterID: 2435