Growth and Analysis of Auxotroph System in E. coli
The W3 and Y3 strains (tryptophan ad tyrosine auxotrophs) that we obtained from the Lin Lab at the University of Michigan had already been studied in a paper published earlier this year.
A Programmable Escherichia coli Consortium via Tunable Symbiosis . They showed some experimental analysis which were the first steps at showing that these strains could be induced at varying levels to get a range of ratios between the two strains.
Based on comments made in the discussion section of the Kerner paper, we believed that it was necessary to determine whether the population of the two strains could be determined based on an equation relating the total OD of the two strains and the YFP reading from one of the strains (Y3). For this reason we created a standard curve of YFP fluorescence versus cell density.
We were able to create our own version of the model presented in the Kerner 2012 paper, using parameters we found in the literature and obtained through our own data collection. Additionally, we determined the ratios of the two strains through data that we collected.
A 3D surface of that graph was obtained and a slice of the graph is shown here:
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