Honors Theses
Date of Award
Spring 5-10-2025
Document Type
Undergraduate Thesis
Department
Biology
First Advisor
Colin Jackson
Second Advisor
Peter Zee
Third Advisor
John Samonds
Relational Format
Dissertation/Thesis
Abstract
Coastal environments of the Gulf of Mexico host diverse and dynamic microbial communities essential for biogeochemical cycling, yet the fine-scale environmental drivers of microbial function and community structure in these systems remain underexplored. This study investigated the relationships between sand moisture content, microbial extracellular enzyme activity, and bacterial community composition along beach transects on Biloxi East Beach, Mississippi. Sand was sampled at five points along four transects spanning a gradient from submerged intertidal zones to dry upper beach sands. Extracellular enzyme activities linked to carbon, nitrogen, and phosphorus cycling (β-glucosidase, N-acetylglucosaminidase, phosphatase, phenol oxidase, and peroxidase) were measured, and bacterial communities were analyzed via 16S rRNA gene sequencing. Enzyme activity varied significantly by beach position, with highest activities at mid-transect sites with intermediate moisture content. However, moisture content alone did not significantly predict enzyme activity. Bacterial community composition and diversity varied significantly with position on the beach, with distinct microbial communities along the moisture gradient. These results suggest that while beach position and moisture gradients influence microbial community diversity and function, the relationships are complex and may not be linear. This study advances understanding of microbial ecology in coastal systems and highlights the importance of fine-scale environmental gradients in shaping ecosystem function.
Recommended Citation
Basha, Elizabeth, "Fine-scale Spatial Patterns in Microbial Activity and Community Composition in Shoreline Marine Sediments" (2025). Honors Theses. 3248.
https://egrove.olemiss.edu/hon_thesis/3248
Creative Commons License
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