Full metadata
Title
Approaches to engineering Synechocystis for biofuel production with emphasis on electron transport modifications
Description
The basic scheme for photosynthesis suggests the two photosystems existing in parity with one another. However, cyanobacteria typically maintain significantly more photosystem I (PSI) than photosystem II (PSII) complexes. I set out to evaluate this disparity through development and analysis of multiple mutants of the genetically tractable cyanobacterium Synechocystis sp. PCC 6803 that exhibit a range of expression levels of the main proteins present in PSI (Chapter 2). One hypothesis was that the higher abundance of PSI in this organism is used to enable more cyclic electron flow (CEF) around PSI to contribute to greater ATP synthesis. Results of this study show that indeed CEF is enhanced by the high amount of PSI present in WT. On the other hand, mutants with less PSI and less cyclic electron flow appeared able to maintain healthy levels of ATP synthesis through other compensatory mechanisms. Reduction in PSI abundance is naturally associated with reduced chlorophyll content, and mutants with less PSI showed greater primary productivity as light intensity increased due to increased light penetration in the cultures. Another question addressed in this research project involved the effect of deletion of flavoprotein 3 (an electron sink for PSI-generated electrons) from mutant strains that produce and secrete a fatty acid (Chapter 3). Removing Flv3 increased fatty acid production, most likely due to increased abundance of reducing equivalents that are key to fatty acid biosynthesis. Additional components of my dissertation research included examination of alkane biosynthesis in Synechocystis (Chapter 4), and effects of attempting to overexpress fibrillin genes for enhancement of stored compounds (Chapter 5). Synechocystis is an excellent platform for metabolic engineering studies with its photosynthetic capability and ease of genetic alteration, and the presented research sheds light on multiple aspects of its fundamental biology.
Date Created
2017
Contributors
- Moore, Vickie (Author)
- Vermaas, Willem (Thesis advisor)
- Wang, Xuan (Committee member)
- Roberson, Robert (Committee member)
- Gaxiola, Roberto (Committee member)
- Bingham, Scott (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
xi, 144 pages : illustrations (chiefly color)
Language
eng
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.44171
Statement of Responsibility
by Vicki Moore
Description Source
Retrieved on March 21, 2018
Level of coding
full
Note
thesis
Partial requirement for: Ph.D., Arizona State University, 2017
bibliography
Includes bibliographical references (pages 126-138)
Field of study: Biology
System Created
- 2017-06-01 01:58:23
System Modified
- 2021-08-26 09:47:01
- 3 years 2 months ago
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