MICROBIAL METABOLISM AND COMMUNITY SUCCESSION FOLLOWING SEDIMENT RESUSPENSION

Organic matter deposited in marine sediments can be sequestered over geological timescales, but through physical processes may be resuspended and consequently fuel microbial heterotrophy.  Microbial responses to resuspended organic matter is not well understood but is potentially controlled by the inherent reactivity of the organic carbon, the carbon degradation capabilities of the present microbial communities, and/or ambient physicochemical characteristics including oxygen and nutrient availability. Here, we performed a series of fjord and continental shelf sediment resuspension experiments to investigate resuspended carbon reactivity, microbial enzymatic responses, and microbial community succession. Surface and subsurface sediments were mixed with bottom waters to simulate sediment resuspension and tracked at multiple time scales (days vs. months). We will present data on measured enzyme activities including various exo- and endo-acting peptidases, glucosidases, and phosphatase to quantify changes in metabolic needs upon microbial exposure to resuspended carbon. In addition, we will present carbon reactivity measurements based on oxygen consumption following resuspension, as well as community composition based 16S rRNA gene amplicon sequencing. These data provide a comprehensive microbial and biogeochemical view of carbon-related processes that ensue following sediment resuspension.

Presentation Preference: Poster

Primary Presenter: Ava Niemczyk, Lehigh University (aen226@lehigh.edu)

Authors:

Ava Niemczyk, Lehigh University  (aen226@lehigh.edu)

Rebecca James, Universite Libre de Bruxelles  (rebecca.james@ulb.be)

Sebastiaan van de Velde, University of Otago  (sebastiaan.vandevelde@otago.ac.nz)

Jake Reardon, University of Southern Denmark  (jake.m.reardon@gmail.com)

John Paul Balmonte, Lehigh University  (jpb422@lehigh.edu)