Title:
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Development of a microbioreactor for synthetic biology applications
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This thesis details the development of a microbioreactor with application in synthetic biology. The aim was the development and engineering characterization of an instrumented microbioreactor system that could aid scientists in the phenotypic analysis of genetically engineered strains. An existing prototype of a microbioreactor was modified to improve mixing. The microbioreactor was then critically evaluated by: assessing two mixing methods, assessing the prototype against a second reactor design option, characterizing oxygen transfer and mixing, comparing performance with a commercially available minibioreactor, and successfully culturing the genetically modified, gram-positive bacterium, Staphylococcus carnosus using the chemostat mode of operation. Engineering characterization of the device was used to inform the selection of process conditions for chemostat studies. KLa values of ~ 113 h-1 and mixing times of ~ 1.2 s were achieved. Residence time distribution analysis demonstrated operation under nearly ideally mixed conditions with ~ 1% of stagnant volumes. Continuous fermentations using different dilution rates and glucose feed concentrations demonstrated the ability of the system to control the growth rate and create a controlled change in OD concentration, respectively. The oxygen uptake rate (OUR) was determined at two dilution rates, which are to the knowledge of the author, the first OUR values reported for Staphylococcus carnosus in a microchemostat. Overall, the results provided a more complete engineering understanding of the device, which will facilitate further improvement of the microbioreactor set up to create a high-throughput experimental platform capable of rapidly screening for growth conditions.
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