Dominick, Corey
(2020)
The Motility and Chemotactic Response of Escherichia coli.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
We have studied several aspects of the chemotactic network of Escherichia coli, as well as the
motility of these cells near solid surfaces. In the first chapter, we develop a novel assay for our
research that takes advantage of a "self-trapping" phenomenon in which fully motile bacteria
rotate in place at a solid boundary. We then use this assay to study the chemotactic and
thermotactic response to impulse stimuli, quantifying the response of the bacteria to heat
and serine. In addition, our data illustrates the amplification in the chemotactic network
and the motor.
We provide evidence that CheZ is actively regulated in its role as the network phosphatase.
In chapter 4, we further study the impulse response at the lower limit of attractant
concentrations and find that bacteria are capable of sensing and responding to single
molecules of amino acids. Our data is compared to existing models with the aid of a calculation
of diffusion inside the cell. The fit of the model is further improved under a modification
inspired by our finding that CheZ is actively regulated. Finally we use our self-trapping assay
to understand transitions between the run and tumble states in wild-type bacteria, and
show that a single filament organizes the
flagella bundle and drives the transitions between
the run and tumble states of bacterial swimming.
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Details
Item Type: |
University of Pittsburgh ETD
|
Status: |
Unpublished |
Creators/Authors: |
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ETD Committee: |
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Date: |
8 June 2020 |
Date Type: |
Publication |
Defense Date: |
21 January 2020 |
Approval Date: |
8 June 2020 |
Submission Date: |
7 April 2020 |
Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
Number of Pages: |
125 |
Institution: |
University of Pittsburgh |
Schools and Programs: |
Dietrich School of Arts and Sciences > Physics |
Degree: |
PhD - Doctor of Philosophy |
Thesis Type: |
Doctoral Dissertation |
Refereed: |
Yes |
Uncontrolled Keywords: |
Biophysics
Chemotaxis |
Date Deposited: |
08 Jun 2020 16:08 |
Last Modified: |
08 Jun 2020 16:08 |
URI: |
http://d-scholarship.pitt.edu/id/eprint/38619 |
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