Thesis Defense Announcement
To:  The George Mason University Community

Candidate: William T. Boswell
Program: Master of Science in Biology

Date:   Friday April 6, 2012
Time:   10:00 a.m.
Place:  George Mason University, Prince William campus
	     Bull Run Hall, Room 249
Thesis Chair:  Dr. Monique van Hoek

Title: "Investigating the Molecular Determinants of PHB Biosynthesis in Vibrio Campbellii"

A copy of the thesis is on reserve in the Johnson Center Library, Fairfax campus.  The thesis will not be read at the meeting, but should be read in advance. All members of the George Mason University community are invited to attend.


Polyhydroxyalkanoates (PHA) or bioplastics are small carbon and energy storage polymers commonly found in the bacterial cytosol. The most-characterized PHAs are the poly-hydroxy-butyrates (PHBs), and the biodegradable properties of PHBs make them attractive alternatives to conventional petroleum based plastics. Bacteria produce PHBs in carbon- rich environments when other nutrients such as nitrogen are limited. PHB biosynthesis in the model organism Escherichia coli is controlled by the AtoS-AtoC two-component system (TCS). The AtoS-AtoC TCS directly regulates expression of the atoDAEB operon that encodes proteins responsible for PHB biosynthesis. Similar to E. coli, studies have demonstrated that certain Vibrio species, specifically Vibrio harveyi, can also produce PHBs. Analysis of the V. campbellii BAA-1116 genome suggests that it too possesses homologs of E. coli atoS, atoC, and atoDAEB.
Therefore, it was the aim of this project to characterize the putative ato system in V. campbellii BAA-1116. To elucidate the role of the putative ato genes in the biosynthesis of PHB in V. campbellii BAA-1116, in-frame deletion mutants were constructed. Using the in-frame deletion mutants, RT-PCR, global phenotypic microarray analysis, and immunohistochemistry demonstrated the putative ato genes are not involved with PHB biosynthesis in V. campbellii BAA-1116.