Dissertation/Thesis Abstract

Influences of Particulate Matter Transport, Export, and Sedimentation on Microbial Community Ecology
by Yoshimura, Kristin Michelle, Ph.D., University of Delaware, 2019, 235; 13859788
Abstract (Summary)

It is well-documented that particulate prokaryotic communities differ from their free-living counterparts, yet the ecology of particle-associated bacteria is better understood than of the archaea. In this dissertation I utilize a coastal site (Broadkill River, Lewes, DE) to separately examine the archaeal and bacterial ecology on marine particulate matter and investigate how the ecologies are influenced by a particle discharge gradient. I further examine an open ocean site (North Pond, Mid-Atlantic Ocean) for particle-associated archaea and bacteria and their community changes with depth and additionally examine archaeal community dynamics over a short time series in the open ocean, which has not previously been possible due to the logistics of oceanic research. Lastly, I investigate the development of sedimentary microbial communities following the settlement of particulate matter and its associated communities.

Archaeal and bacterial communities were shown to respond differently to environmental stressors including particle size, oxygen, salinity, and particle depth, indicating in both coastal and open ocean environments that particle-associated archaeal and bacterial ecologies are inherently unique. Archaeal contributions to open ocean prokaryotic communities were demonstrated to be dynamic on the order of days to weeks, though depth and particle size were stronger influences on community structure than sampling day. Archaeal abundances in the deep sea were measured to be one order of magnitude lower than bacterial abundances, contradicting historic reports from the Atlantic and Pacific Ocean that estimate archaea to make up 40–50% of all deep sea prokaryotes. Finally, using modern sequencing and analysis methods, I show that in both coastal and open ocean environments, sedimentary communities develop from particle-associated communities, but that these communities are seeded by the ultra rare particle-associated community.

Indexing (document details)
Advisor: Biddle, Jennifer
Commitee: York, Joanna, Coyne, Kathryn, Kerkhof, Lee, Shah Walter, Sunita
School: University of Delaware
Department: Marine Studies
School Location: United States -- Delaware
Source: DAI-B 81/1(E), Dissertation Abstracts International
Source Type: DISSERTATION
Subjects: Microbiology, Ecology
Keywords: Archaea, Bacteria, Connectivity, Microbial ecology, Particles
Publication Number: 13859788
ISBN: 9781085558709
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