USING EMPIRICAL DYNAMIC MODELING AND MICROBIAL ISOLATES TO EXPLORE CLIMATE RESPONSES IN THE DEGRADATION OF ORGANIC MATTER FROM THE DIATOM SKELETONEMA.

Bertram-Chuxuan Ji¹ †, Jiaqian Li^1,3, Jean Philippe Gibert², Akshaya Mohan¹, Rane Parr¹, Dana E. Hunt^1,2,4, 1 Marine Laboratory, Duke University, Beaufort, NC, USA² Department of Biology, Duke University, Durham, NC, USA³ School of Environmental Science & Engineering, Center for Marine Environmental Ecology, Tianjin University, China⁴ Civil & Environmental Engineering, Duke University, Durham, NC, USA   † Presenter Bertram.ji@duke.edu;   The Piver’s Island Coastal Observatory (PICO) has been sampled for more than a decade to capture environment and microbiome responses to environmental change and disturbance. While observational data can develop predictions of microbial interactions and responses to future climate conditions, we are developing a tractable synthetic microbial community to explore global change impacts on microbial activity and interactions. In order to better understand competition and cooperation in microbial degradation of organic matter (from the diatom Skeletonema), here, we develop a culture library of bacterioplankton and heterotrophic eukaryotes (Labyrinthulomycetes) from PICO seawater and a Skeletonema costatum lysate enrichment. First, we used empirical dynamic modeling (EDM) of uncultured microbial diversity (bacterioplankton, Labyrinthulomycetes, fungi) to identify potential interactions with Skeletonema. While fungi were not strong interactors in the system, bacterial taxa such as Flavobacteriaceae, Cryomorphaceae, and SAR86 clade exhibit strong inhibitory effects on Skeletonema. In contrast, the AEGEAN-169 clade demonstrates variable interactions that are context-dependent, showing both positive and negative effects. EDM results were used to target interaction-relevant bacterioplankton and Labyrinthulomycetes isolations. This culture library provides a valuable resource for exploring how these model microbes interact to degrade algal organic matter and how these interactions may change under global change, specifically warming.

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Primary Presenter: Bertram Ji, Duke University (bertram.ji@duke.edu)

Authors:

Bertram-Chuxuan Ji, Marine Laboratory, Duke University  (bertram.ji@duke.edu)

Jiaqian Li, School of Environmental Science & Engineering, Center for Marine Environmental Ecology, Tianjin University  (jiaqian.li@duke.edu)

Jean-Philippe Gibert, Department of Biology, Duke University  (jean.gibert@duke.edu)

Akshaya Mohan, Marine Laboratory, Duke University  (akshaya.mohan@duke.edu)

Rane Parr, Marine Laboratory, Duke University  (rane.parr@duke.edu)

Dana Hunt, Marine Laboratory, Duke University  (dana.hunt@duke.edu)