Team:ETH Zurich/Modeling/Analytical Approximations
From 2013.igem.org
Steady State AHL Gradient Approximation
In the reaction-diffusion model we have formalized the gradient establishment and we solved the resulting partial differential equation numerically. Now, the aim is to derive a suitable analytical approximation for a single mine colony.
Kolmogorov-Petrovsky-Piskounov Equation
A reaction–diffusion equation concerning the concentration of a single molecule in one spatial dimension is known as the Kolmogorov-Petrovsky-Piskounov Equation. In our case, the equation for AHL has the following general structure:
\begin{align} \frac{\partial AHL(x,t)}{\partial t} = Diff(AHL(x,t),x) + R(AHL(x,t)) \end{align}
We were interested in the AHL gradient that can be established by a single colony ( located at $x = 0$) on an agar plate, ending up with a less general form of the reaction-diffusion model for AHL:
\begin{align} \frac{\partial AHL}{\partial t} = C_{agar} \cdot D_{AHL} \frac{\partial^2 AHL}{\partial x^2} + DF \cdot (\alpha_{AHL} \cdot [LuxI]-d_{AHL,i} \cdot [AHL]) - d_{AHL,e} \cdot [AHL] \end{align}
Considering as boundary condition that the concentration at the mine stays constant, we have:
\begin{align}
[AHL](x=0) = [AHL]_{MineCell,ss}
\end{align}