Team:KAIST-Korea/Projects/report 1

1. Overview
            Our system, E.Casso is composed of two modules. Each module is a different strain of E. coli. We introduced the modules into disparate strains of E.coli because it is usually easier to engineer something by adopting the ‘divide and conquer’ strategy. The modules perform the following tasks: The first type (Brush E. coli) produces signals that determine the color among green, cyan, yellow, and red generated by adjacent, second type of E. coli. This is achieved through an inherent mechanism by which E. coli naturally communicate with each other, the quorum sensing. By exchanging signaling molecules termed quorum, E. coli can coordinate gene expression as a colony according to its local density. The second type (Dyestuff E. coli) receives quorum from the first type and produces corresponding fluorescent proteins. It also amplifies the signal made by the type 1 module and propagates it to the surrounding E. coli. In essence, we utilize cell-cell communication to coordinate the collective behavior of E. coli.
            This is akin to soaking a brush with any one of four colors and compressing it firmly against a point on a paper. As time goes by, the blob of paint on the paper will spread. Our genetically engineered E. coli will draw abstract paintings in a similar manner.
            The modeling procedure is divided into four parts.
      A.Modeling the production of quorum by the first type of E. coli (Brush E. coli): Objective – observe that Brush E. coli produce enough quorums per some interval of time.
      B.Modeling the diffusion of quorum: Objective – note the time scale in which quorum propagates from Brush E. coli to Dyestuff E. coli.
      C.Modeling the production of fluorescent proteins by the Dyestuff E. coli upon receiving quorum and projecting the time it takes for a noticeable amount of fluorescence to accumulate: Objective – observe the time it takes for enough fluorescence to build up.
      D.Modeling how the variation in E. coli distribution affects the final outcome: Objective – note how the ratio of the two E. coli and the method of seeding affect the resultant painting.