• Login
    View Item 
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UMB Digital ArchiveCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    Display statistics

    Survival of a Polyextremophilic Archaeon and Function of Its Enzyme in Potentially Astrobiological Conditions

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Laye_umaryland_0373N_10967.pdf
    Size:
    1.423Mb
    Format:
    PDF
    Download
    Author
    Laye, Victoria Janet
    Advisor
    DasSarma, Shiladitya
    Date
    2018
    Type
    dissertation
    
    Metadata
    Show full item record
    Abstract
    Haloarchaea are extremophilic microorganisms used as models for life in niche environments on Earth, Mars, and other planets. We compared growth of Halorubrum lacusprofundi, a cold-adapted isolate from Vestfold Hills, Antarctica, with Halobacterium sp. NRC-1, a mesophilic laboratory strain. Both tolerated concentrations of magnesium and perchlorate higher than expected on Mars. These Haloarchaea were exposed to and tolerated stratospheric conditions. Psychrophilic Halorubrum has a better survival rate than Halobacterium after freeze-thaw. Cold-active β-galactosidase from Halorubrum was used as a model to establish effects of inhibitory conditions. The enzyme was more inhibited by magnesium. Cold-activity of the enzyme was investigated through bioinformatics, genomics, and mutagenesis by identifying divergent amino acids and creating single amino acid mutations. Importance of the residues for cold activity was tested and confirmed using steady-state kinetics. Based on this work, Halorubrum and its enzyme are ideal models for studying adaptation in polyextreme environments on Earth and elsewhere.
    Description
    University of Maryland, Baltimore. Marine-Estuarine-Environmental Sciences. M.S. 2018
    Keyword
    Haloarchaea
    Euryarchaeota
    Extreme Environments
    Identifier to cite or link to this item
    http://hdl.handle.net/10713/8009
    Collections
    Theses and Dissertations School of Medicine
    Theses and Dissertations All Schools

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Policies | Contact Us | UMB Health Sciences & Human Services Library
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.