Team:GeorgiaTech/Systems Modeling

Figure (A) depicts the approach taken to model E. coli heat production and localization using AOX in a 'dry' plated culture. In order to determine the steady state temperature of E. coli colonies expressing heat, colonies are approximated as a single layer composed of a certain amount of heat producing cells with thermal conductivity k1. The heat produced in this situation is transferred by conduction with the media (agar) below the colonies and by convection with the air and an equilibrium temperature will be reached.

Figure (B) presents the modeling of E. coli on a dry, plated culture in the form of a circuit diagram. The circuit diagram represents the CspA or HyBb promoter as a switch which would activate the expression of AOX pathway in the cell during cold shock. As the cell starts producing heat, mainly through AOX pathway, the heat starts to create a flux through the E. coli layer and release heat into the environment (basically in the media through conduction and in the air through convection). Since, the heat flows from E. coli in the media, it creates a temperature gradient across the whole plate due to the resistance encountered by it. These resistances are mainly due to conduction in media and convection in air which can be combined to single resistance as they are in parallel orientation to each other.