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The Impact of Energy Availability and Substrate Complexity on Anaerobic Microbial Communities in Marine Sediment


Lim, Sujung (2024) The Impact of Energy Availability and Substrate Complexity on Anaerobic Microbial Communities in Marine Sediment. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/67j6-4885.


This thesis probes the interplay of organic matter complexity (Chapters 1 and 2) and local redox gradients (Chapter 3) with the community structure and function of the anaerobic marine sediment microbiome. Deep marine sediments, despite being generally organic-poor, harbor a vast diversity of microorganisms that are critical to the global nutrient cycle. Transient nutrient inputs such as whale falls result in hotspots of microbial community activity in an environment that normally processes heavily degraded organic material from the upper ocean. These organic loading events result in transitions down redox gradients and dynamic shifts in the local energy availability of the microbial communities. Through in situ seafloor and laboratory microcosm experiments, we provide insights into the impact of energy availability and carbon complexity on maintaining hierarchical and complex community interactions, community activity, and systematic and functional diversity.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:marine sediment ecology, microcosm, microbial community structure, environmental microbiology, chitin
Degree Grantor:California Institute of Technology
Division:Geological and Planetary Sciences
Major Option:Geobiology
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Orphan, Victoria J.
Thesis Committee:
  • Sessions, Alex L. (chair)
  • Leadbetter, Jared R.
  • Fischer, Woodward W.
  • Orphan, Victoria J.
Defense Date:12 March 2024
Funding AgencyGrant Number
Simons Foundation542393
Center for Dark Energy Biosphere Investigations66468073
Record Number:CaltechTHESIS:04172024-164449548
Persistent URL:
Lim, Sujung0000-0001-6040-729X
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:16357
Deposited By: Sujung Lim
Deposited On:16 May 2024 17:20
Last Modified:23 May 2024 18:34

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