$~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\newcommand{\MyColi}{{\small Mighty\hspace{0.12cm}Coli}}
\newcommand{\Stabi}{\small Stabi}$
$\newcommand{\EColi}{\small E.coli}
\newcommand{\SCere}{\small S.cerevisae}\\[0cm]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\newcommand{\PI}{\small PI}$
$\newcommand{\Igo}{\Large\mathcal{I}}
\newcommand{\Tgo}{\Large\mathcal{T}}
\newcommand{\Ogo}{\Large\mathcal{O}}
~$
Example of a hierarchical menu in CSS
The population dynamics modelling showed first that the impact of the antibiotics must be included in a realistic model, because without antibiotics, E.coli bacteria would finish without the plasmids necessary to activate our Mighty Coli system $\small\&$ secondly that the bacterial population grows at a particulary high rate in the beginning, but rapidly it converges until a constant quantity. Consequently, it is important to add bacterial food enough into the LB medium and to select the more productive bacteria, f.e. using a bioreator containing initially non-productive bacteria and where Mighty Coli could work.
The TA system modelling consisted to evaluate in which circumstances (sets of kinetic parameters) Mighty Coli is useful after estimating the degree of cooperativity in the system where antitoxin (gene situated in a plasmid constanlty maintained generation by generation, with a promoter not influenced by the medium) is unstable in comparison with the toxin (gene situated in another plasmid with a promoter activated or repressed by the medium), but is necessary for E.coli to survive. A Michaelis-Menten statistics was chosen and the equations were solved at stationary state to obtain analytical expressions between the parameters (and depending of the PI to produce, but also of the kind of bioreactor).
The p2A modelling: estimating the cleavage rate of the 2A peptide chosen, the frequency of the mutations and the ratio [Tox]/[Anti-Tox], we obtained the boost of the production in a bioreactor using Mighty Coli (with a Toxin gene situated in the bacterial chromosome of E.coli, annihilated by an Anti-Tox gene activation with a plasmid maintained in the medium) in comparison with using the classical Stabi system, for in vivo protein production. We concluded that there are bioreactors (f.e. producing RFP fluorescent proteins) where Mighty Coli is not really useful, but that for some specified proteins of interest (big or cumbersome proteins produced by E.coli, f.e. ApoA), our system increases the producing rate of the PI.
A future continuation of our project could be to study accurately the 2A peptides to refine our current model and to build new Biobricks using different 2A peptides, ready to be applied in bioreactors.
"
- Université Libre de Bruxelles -
