- Title Information
- Title
- Phylogenetic and Phenotypic Studies of the Extremophile Chroococcidiopsis (Cyanobacterium). A Foundation for Synthetic Biology in Space.
- Name:
Personal
- Name Part
- Cumbers, John Robert
- Role
- Role Term:
Text
- creator
- Origin Information
- Copyright Date
- 2012
- Physical Description
- Extent
- xvi, 194 p.
- digitalOrigin
- born digital
- Note
- Thesis (Ph.D. -- Brown University (2012)
- Name:
Personal
- Name Part
- Tatar, Marc
- Role
- Role Term:
Text
- Director
- Name:
Personal
- Name Part
- Rothschild, Lynn
- Role
- Role Term:
Text
- Director
- Name:
Personal
- Name Part
- Dunn, Casey
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Patterson, David
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Weinreich, Daniel
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Wessel, Gary
- Role
- Role Term:
Text
- Reader
- Name:
Corporate
- Name Part
- Brown University. BIOMED: Molecular Biology, Cell Biology, and Biochemistry
- Role
- Role Term:
Text
- sponsor
- Genre (aat)
- theses
- Subject
- Topic
- Chroococcidiopsis
- Subject
- Topic
- extremophile
- Subject
- Topic
- halophile
- Subject
- Topic
- halophyly
- Subject
- Topic
- halotolerance
- Subject
- Topic
- moderate halophile
- Subject
- Topic
- phylogenetics
- Subject
- Topic
- Pleurocapsales
- Subject
- Topic
- salt tolerance
- Subject
- Topic
- radiation resistance
- Subject
- Topic
- UV tolerance
- Subject
- Topic
- ISRU
- Subject
- Topic
- BISRU
- Subject
- Topic
- in situ resource utilization
- Subject
- Topic
- biological in situ resource utilization
- Subject (FAST)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/885738")
- Topic
- Cyanobacteria
- Subject (FAST)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/919063")
- Topic
- Extreme environments--Microbiology
- Subject (FAST)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/950709")
- Topic
- Halophilic organisms
- Subject (FAST)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1062326")
- Topic
- Phylogeny
- Subject (FAST)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1086967")
- Topic
- Radiation tolerance
- Subject (FAST)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1762461")
- Topic
- Synthetic biology
- Record Information
- Record Content Source (marcorg)
- RPB
- Record Creation Date
(encoding="iso8601")
- 20121023
- Language
- Language Term:
Code (ISO639-2B)
- eng
- Language Term:
Text
- English
- Abstract
- Understanding the mechanisms used by organisms living in extreme environments on Earth is a first step towards rationally designing organisms for living in space. The design of complex function is a goal of synthetic biology. If humanity is destined to settle the solar system, then engineered biology could be a valuable tool for producing consumables from resources found in space (known as biological in situ resource utilization or ISRU/BISRU). This thesis builds a foundation for synthetic biology in space and the engineering of organisms for survival and productivity there. <br/>
<br/>
To understand the limits of life I surveyed the distribution, diversity and tolerance to extreme conditions of a number of extremophilic cyanobacteria. I chose the genus Chroococcidiopsis (Geitler, 1933) because it is known to be radiation and desiccation tolerant and has been previously proposed as a suitable organism for terraforming Mars. <br/>
<br/>
Working with extremophiles can be challenging due to abnormal physiology and growth conditions. In this thesis I describe assays that were developed for measuring growth with optical density in aggregating cells such as Chroococcidiopsis. I also developed an assay for measuring growth and survival of cyanobacteria on agar plates.<br/>
<br/>
To understand the evolution of Chroococcidiopsis, I sequenced four genetic markers from 15 species isolated from different environments. I then reconstructed the evolutionary history of the genus by producing phylogenetic trees. From this phylogeny species were selected for detailed phenotypic analysis of tolerance to salt, desiccation, ultraviolet radiation (UVR), oxidative damage and freeze thawing. <br/>
<br/>
The results revealed a moderately halophilic clade of Chroococcidiopsis, demonstrating that the genus is polyphyletic based on this phenotype. The species also showed a range of tolerances to UVR. CCMP 1991 (Hawaii) and CCMP 3184 (Samoa) were more resistant than other previously uncharacterized species. These results suggest that antioxidants or pigments could play a role in UVR protection. A DNA repair system, occurring faster in the light than in the dark could also be responsible and may be linked to freeze thaw survival.
- Identifier:
DOI
- 10.7301/Z0VX0DTV
- Access Condition:
rights statement
(href="http://rightsstatements.org/vocab/InC/1.0/")
- In Copyright
- Access Condition:
restriction on access
- Collection is open for research.
- Type of Resource (primo)
- dissertations