The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH

Bibliographic Details
Main Author: Brzoska, Ryann Michelle
Language:English
Published: Miami University / OhioLINK 2015
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=miami1437753281
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-miami14377532812021-08-03T06:32:21Z The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH Brzoska, Ryann Michelle Microbiology Ecology Biology Environmental Science Artificial microbial community consortia Oak Ridge interactions evolution long-term uranium low pH Sediminibacterium genomics physiology coculture Uranium-contaminated environments contain microbial communities capable of immobilizing uranium. There is evidence that some bacterial communities are capable of immobilizing higher concentrations of uranium than individual species. However, the interactions between bacterial species contributing to increased uranium immobilization are not understood. Therefore, the goal of this study was to identify interactions between species in an artificial community and assess their influence on uranium immobilization. Bacterial species previously isolated from the uranium-contaminated subsurface at Oak Ridge, Tennessee, were characterized both individually and in a mixed community in the presence and absence of uranium or low pH. Growth of individual bacterial strains in the presence of uranium or low pH revealed two Sediminibacterium strains, Sediminibacterium spp. OR43 and OR53, with different degrees of tolerance towards uranium. The main physiological or genomic difference between the Sediminibacterium strains was the sensitivity of Sediminibacterium sp. OR43 to uranium concentrations > 200 µM uranium. Sediminibacterium sp. OR53 was chosen along with Caulobacter sp. OR37, Ralstonia sp. OR214, and Rhodanobacter sp. OR444 to be a part of an artificially assembled community. The productivity of the community was assessed by monitoring the optical density and the abundance of each species in the community in the presence or absence of 200 µM uranium at pH 4.5 (pH4.5) or 7 (pH7) for 30 weeks (~300 generations). At pH7 and pH4.5, all strains were present, but the strain tolerant to the lowest pH, Ralstonia sp. OR214, was the most abundant. The presence of uranium selected for the uranium-tolerant strains, Sediminibacterium sp. OR53 and Caulobacter sp. OR37. Moreover, when a subculture of the consortium at pH 7 with uranium (pH7U) was transferred into pH7 without uranium, the uranium-sensitive strains did not recover. Re-isolated strains of Caulobacter spp. OR37 and Sediminibacterium spp. OR53 from the pH7U condition showed increased growth in coculture that did not correlate with an increase in uranium immobilization when compared to individual strains. Taken together, our results indicate that commensalistic and competitive interactions may develop between microbial species and impact growth and uranium immobilization, which are important for microbial communities considered for the purpose of bioremediation. 2015-07-27 English text Miami University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=miami1437753281 http://rave.ohiolink.edu/etdc/view?acc_num=miami1437753281 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Microbiology
Ecology
Biology
Environmental Science
Artificial microbial community
consortia
Oak Ridge
interactions
evolution
long-term
uranium
low pH
Sediminibacterium
genomics
physiology
coculture
spellingShingle Microbiology
Ecology
Biology
Environmental Science
Artificial microbial community
consortia
Oak Ridge
interactions
evolution
long-term
uranium
low pH
Sediminibacterium
genomics
physiology
coculture
Brzoska, Ryann Michelle
The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH
author Brzoska, Ryann Michelle
author_facet Brzoska, Ryann Michelle
author_sort Brzoska, Ryann Michelle
title The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH
title_short The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH
title_full The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH
title_fullStr The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH
title_full_unstemmed The Effects of Long-Term Exposure of an Artificially Assembled Microbial Community to Uranium or Low pH
title_sort effects of long-term exposure of an artificially assembled microbial community to uranium or low ph
publisher Miami University / OhioLINK
publishDate 2015
url http://rave.ohiolink.edu/etdc/view?acc_num=miami1437753281
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