Engineering genetically controlled microbial consortia

dc.contributor.advisorBennett, Matthewen_US
dc.contributor.advisorBeckingham, Kathleenen_US
dc.creatorChen, Yeen_US
dc.date.accessioned2017-07-31T16:36:40Zen_US
dc.date.available2017-07-31T16:36:40Zen_US
dc.date.created2016-08en_US
dc.date.issued2016-06-24en_US
dc.date.submittedAugust 2016en_US
dc.date.updated2017-07-31T16:36:40Zen_US
dc.description.abstractTo date, the majority of synthetic gene circuits have been constructed to operate within single, isogenic cellular populations. Two of the toughest challenges for synthetic biologists to achieve complicated multi-strain systems are the limited choice of inducible signals and tuning regulatory components within a gene circuit to elicit desired outputs. Here, we describe a method that allows one to tune the dynamic range in a motif based construction of promoters with regulatory elements. To do this, we first assembled and then tested a library of promoters using different -10 and -35 sites taken from endogenous promoters within Escherichia coli. By mixing and matching the -10 and -35 sites, we were able to create a large number of ligand-inducible promoters exhibiting a wide variety of dynamic ranges. Using this method, we developed an orthogonal, tightly controlled two-signaling system. Then, we used two genetically distinct populations of Escherichia coli and this signaling system to engineer a bacterial consortium that exhibits robust oscillations in gene transcription. When co-cultured in a microfluidic device, the two strains form coupled positive and negative feedback loops at the population-level. The interacting strains exhibit robust, synchronized oscillations that are absent if either strain is cultured in isolation. We further used a combination of mathematical modeling and targeted genetic perturbations to better understand the roles of circuit topology and regulatory promoter strengths in generating and maintaining these oscillations. We found that the dual-feedback topology was robust to changes in promoter strengths and fluctuations in the population ratio of the two strains. These findings demonstrate that one can program population-level dynamics through the genetic engineering of multiple cooperative strains and point the way towards engineering complex synthetic tissues and organs with multiple cell types.en_US
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationChen, Ye. "Engineering genetically controlled microbial consortia." (2016) Diss., Rice University. <a href="https://hdl.handle.net/1911/95582">https://hdl.handle.net/1911/95582</a>.en_US
dc.identifier.urihttps://hdl.handle.net/1911/95582en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.subjectpromoter engineeringen_US
dc.subjecthybrid promoteren_US
dc.subjectAND gateen_US
dc.subjectmicrobial consortiaen_US
dc.subjectgenetic oscillatoren_US
dc.subjectmulti-strain systemen_US
dc.subjecttoggle switchen_US
dc.subjectquorum sensingen_US
dc.titleEngineering genetically controlled microbial consortiaen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentBiochemistry and Cell Biologyen_US
thesis.degree.disciplineNatural Sciencesen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophyen_US
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
CHEN-DOCUMENT-2016.pdf
Size:
4.14 MB
Format:
Adobe Portable Document Format
License bundle
Now showing 1 - 2 of 2
No Thumbnail Available
Name:
PROQUEST_LICENSE.txt
Size:
5.84 KB
Format:
Plain Text
Description:
No Thumbnail Available
Name:
LICENSE.txt
Size:
2.6 KB
Format:
Plain Text
Description: