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From 2010.igem.org

Introduction

As a future work of our project the aim is to manipulate the bacteria to produce in environments outside laboratory as a bacteria therapy. Bacteria will produce proteins fusion with cpp (cell penetration peptides) while it is on skin. Two main factors need to be considered here:

• Since bacteria will be outside of lab environment, we need to choose proper assumptions to fit the situation.
• CPP can lead to the bacteria's death at certain concentrations, as they will penetrate the membrane and eventually kill bacteria. So it is crucial to have the bacteria to begin the production when it comes with contact with skin.

We have LacI as repressor, so idea is to have a creme on skin which contains lactose as inducer. As a matter of fact good timing is needed before CPP reaches a critical concentration to kill bacteria. It seems in this scenario we need to take into account possible details such as degradation rates, cell growth, and factors that will effect a stable production such as translational and transcriptional delay.

Therefore, we are aiming to achieve a predicting model for production of protein in our system of bacteria and have the model to describe production is induced in bacteria from the time induction starts until it is dead because of CPPs penetrating bacteria membrane. In this model we will not include or model or try to predict re-pigmentation, because of high complications in target human cells. for further reading about mathematics one can [http://www.biomedcentral.com/1752-0509/3/60| The mathematics of tanning Thingnes J. et al. 2008]

Out of these details, there are some data we need to know in advance. These details include:

• How much lactose is available for bacteria? i. e. Concentration of Lactose on skin
• Production rate for biomolecules in host bacteria
• Allolactose/Lactose degradation rate
• Allolactose/Lactose absorption through skin
• Critical concentration of CPP