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Date Permissions Signed


Date of Award

Fall 2016

Document Type

Masters Thesis

Degree Name

Master of Science (MS)



First Advisor

Moyer, Craig L.

Second Advisor

Fullerton, Heather

Third Advisor

Kodner, Robin

Fourth Advisor

Schwarz, Dietmar, 1974-


The Mariana region exhibits a rich array of hydrothermal venting conditions in a complex geological setting, which provides a natural laboratory to study the influence of local environmental conditions on microbial community structure as well large-scale patterns in microbial biogeography. We used high-throughput amplicon sequencing of the bacterial SSU rRNA gene from 22 microbial mats collected from four hydrothermally active locations along the Mariana Arc and back-arc to explore the structure of lithotrophically-based microbial mat communities in order to better assess the hypothesis that these communities represent hotspots of microbial diversity. The vent effluent was classified as iron- or sulfur-rich corresponding with two distinct community types, dominated by either Zetaproteobacteria or Epsilonproteobacteria, respectively. The Zetaproteobacterial-based communities had the highest richness and diversity, which supports the hypothesis that Zetaproteobacteria are ecosystem engineers. The Epsilonproteobacteria-dominated mats were less abundant and split into two groups based on the prevalence of the genera Sulfurovum/Sulfurimonas or Thioreductor/Lebetimonas, which oxidize or reduce sulfur compounds, respectively. In addition, we also compare two sampling techniques, showing that higher diversity in microbial mats is associated with bulk sampling compared to fine-scale sampling. Overall, we present a comprehensive analysis and new insights into community structure and diversity of the lithotrophically-driven microbial mats from a hydrothermal region associated with high microbial biodiversity.





Western Washington University

OCLC Number


Subject – LCSH

Gram-negative bacteria--Mariana Trench; Hydrothermal vents--Microbiology--Mariana Trench; Microbial diversity--Mariana Trench; Hydrothermal vent ecology--Mariana Trench; Microbial populations--Mariana Trench; Sulfur bacteria--Mariana Trench

Geographic Coverage

Mariana Trench




masters theses




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