Off-campus UMass Amherst users: To download dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users, please click the view more button below to purchase a copy of this dissertation from Proquest.
(Some titles may also be available free of charge in our Open Access Dissertation Collection, so please check there first.)
Microcoleus dominated salt marsh microbial mats: Spirochetes and sulfide
Abstract
Microbial mats are synergistic microbial consortia through which major elements, including sulfur, are cycled due to microbial and geological processes. Depth profiles of pH, O2, sulfide, exopolymeric substances (EPS), and the rate of sulfate reduction were determined in a Microcoleus -dominated marine microbial mat at the Great Sippewissett salt marsh, Massachusetts. In addition, measurements in spirochete enrichments and Spirochaetae litoralis cultures showed sulfide consumption during which polysulfides, thiosulfate, and presumably sulfate formed. These data suggest that spirochetes can play a role in the cycling of sulfur in these mats. The obligate to facultative anaerobic spirochetes consume sulfide to remove oxygen. Furthermore, spirochetes may enhance preservation of microbial mats within the rock record by degrading EPS and producing low molecular weight organic compounds (LMWOC). Both sulfide oxidation (i.e. oxygen removal) and EPS degradation (i.e. production of LMW organic compounds) stimulate the activity of sulfate-reducing bacteria (SRB), which are responsible for the precipitation of calcium carbonate in most lithifying mats.
Subject Area
Microbiology|Biogeochemistry
Recommended Citation
Stephens, Elizabeth A, "Microcoleus dominated salt marsh microbial mats: Spirochetes and sulfide" (2009). Doctoral Dissertations Available from Proquest. AAI3351414.
https://scholarworks.umass.edu/dissertations/AAI3351414