Rhamnolipid Independent Swarming of Pseudomonas aeruginosa

Master's Thesis


Swarming is a surface-associated motility where bacteria spread in groups, often as a precursor to biofilm formation. The bacterium Pseudomonas aeruginosa is known to swarm using its polar flagellum and a self-produced surfactant called rhamnolipid. This thesis details swarming in response to two types of environmental conditions: surface hardness and carbon source. It was found that swarm zone expansion and bacterial population are not linearly correlated during swarming and further that increased surface hardness significantly decreases rhamnolipid-dependent swarming. Secondly, it was found that a rhamnolipid-deficient P. aeruginosa strain swarmed upon the addition of the carbon source glutamate. This is unexpected, as no previous rhamnolipid-deficient swarming has been documented for P. aerguinosa. A mutagenesis approach was used to find gene(s) responsible for this rhamnolipid-independent swarm phenotype by probing for mutants that negate the glutamate swarming effect. Two thousand mutants were screened, twelve of which were found to not swarm with glutamate.


Attribute NameValues
  • etd-12062012-002955

Author Nachiket Kamatkar
Advisor Joshua Shrout
Contributor Shaun Lee, Committee Member
Contributor Robert Nerenberg, Committee Member
Contributor Joshua Shrout, Committee Chair
Degree Level Master's Thesis
Degree Discipline Civil Engineering and Geological Sciences
Degree Name MSBioeng
Defense Date
  • 2012-08-02

Submission Date 2012-12-06
  • United States of America

  • rhamnolipid

  • pseudomonas aeruginosa

  • swarming

  • motility

  • University of Notre Dame

  • English

Record Visibility Public
Content License
  • All rights reserved

Departments and Units


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