Temporal Control

In our project there are 3 forms of temporal control that have been implemented.

Chemical induction: Triggers the production of the polypeptide of interest using IPTG. Effectively 'kicks off' the system once the cell density is high enough.
Autoinduction: Represses encapsulation when glucose levels are high, and kick starts it once glucose is used up. This allows a sufficient amount of protein production to have taken place before the cell focuses its resources on encapsulation.
Thermoinduction: Triggers genome deletion when the temperature is increased. Thermoinduction was necessary, as chemical induction may be blocked by the presence of the capsule (that inhibits diffusion).

The timeline shows the sequence of occurrence of these events:

Explainations and Meanings

Carbon Source Concentration

Glucose

The primary carbon source is glucose, as this is preferentially used by the cell.

Secondary carbon source

This is used by the cell after glucose in the media is depleted.

By carefully balancing the initial concentrations of these carbon sources, The E.ncapsulator will begin Encapsulation (Module 2) only once protein production is at sufficiently high levels.