Between Dec 19, 2024 and Jan 2, 2025, datasets can be submitted to DRUM but will not be processed until after the break. Staff will not be available to answer email during this period, and will not be able to provide DOIs until after Jan 2. If you are in need of a DOI during this period, consider Dryad or OpenICPSR. Submission responses to the UDC may also be delayed during this time.
 

The genetic basis of nitrogen fixation and carbon metabolism in Azotobacter vinelandii

Loading...
Thumbnail Image

Persistent link to this item

Statistics
View Statistics

Journal Title

Journal ISSN

Volume Title

Title

The genetic basis of nitrogen fixation and carbon metabolism in Azotobacter vinelandii

Published Date

2022-06

Publisher

Type

Thesis or Dissertation

Abstract

Natural nitrogen fixation is done primarily by prokaryotes that reduce nitrogen gas(N2) to ammonia (NH3) using the enzyme nitrogenase in a process termed biological nitrogen fixation (BNF). BNF is an alternative to industrial fertilizers that could supply crops with the nitrogen they need, either through symbiotic or free-living associations. Engineering these associations requires an understanding of BNF that extends beyond nitrogenase, to the dynamic suite of proteins that support it. Azotobacter vinelandii is a model organism for studying BNF and contains more than 80 suspected BNF genes, many of which have an unknown function or lack experimental data showing direct BNF association. A. vinelandii is known for being a free-living and aerobic nitrogen fixer, making it both convenient for laboratory studies and biotechnologically relevant. Since most research in this organism has focused on nitrogen fixation, there have been few studies on how various carbon sources are metabolized. Characterizing this metabolism in A. vinelandii in the context of nitrogen fixation would help in engineering viable alternatives to Haber-Bosch. Consequently, this research builds on the contextual knowledge of BNF in A. vinelandii by using transposon mutagenesis to identify genes important to growth and/or nitrogen producing phenotypes. First, we used transposon sequencing (Tn-seq) to determine the genome-wide fitness of genes under diazotrophic, non-diazotrophic, and differing carbon sources. We then used the Tn-seq data from growth on the carbon source galactose to identify two galactose dehydrogenases predicted to complete the pathway of galactose metabolism missed by routine genomic annotation algorithms. Lastly, we explored the gene redundancy of NifA in nitrogenase regulation by characterizing two transposon mutagenesis mutants able to support the growth of algae in co-culture. Overall, this thesis expands on the knowledge of BNF in A. vinelandii by providing genome-wide fitness that quantify individual gene contributions to BNF, carbon metabolism and, which also explores gene redundancy in BNF regulation.

Description

University of Minnesota Ph.D. dissertation. June 2022. Major: Bioproducts/Biosystems Science Engineering and Management. Advisor: Brett Barney. 1 computer file (PDF); x, 141 pages.

Related to

Replaces

License

Collections

Series/Report Number

Funding information

Isbn identifier

Doi identifier

Previously Published Citation

Other identifiers

Suggested citation

Knutson, carolann. (2022). The genetic basis of nitrogen fixation and carbon metabolism in Azotobacter vinelandii. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/241598.

Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.