The project we selected was to design and build a biomechanical printer; composed of a two dimensional plotter equipped with a red laser, software to translate computer images into instructions for the plotter, and E. coli cells engineered to respond to the laser light. Bacteria are spread in a solid lawn on the plate, or mixed in the media before pouring the plate. The response triggered by this biological circuit will produce beta agarase, an enzyme which degrades the agar polymer that the cells rest on. The printer can then be used to “draw” high resolution images on the bacteria with the laser. The bacteria will then dissolve the agar where the laser was shone. This results in Bacterial Lithography, where the dissolved agar forms a picture. Cool eh. We also chose a second project to include in our entry to the competition this year. That is an in Silico Biobrick Evolution system. The purpose of this project is to design a system that will accept user entered parametres and use them to search through the registry database. Using the given parametres the system will try to construct circuts (a series of biobricks) that will produce the desired product. More information on this project can be found in our evoGEM sections. Our team investigated a number of potential projects before selecting our light sensing printer. This section offers a brief outline of some of the ideas we considered.

Our project attacks the following problem: can one engineer viruses to selectively kill or modify specific subpopulations of target cells, based on their RNA or protein expression profiles? This addresses an important issue in gene therapy, where viruses engineered for fine target discrimination would selectively kill only those cells over- or under-expressing specific disease or cancer associated genes. Alternatively, these viruses could be used to discriminate between strains in a bacterial co-culture, allowing strain-specific modification or lysis. This is clearly an ambitious goal, so we brainstormed a simple model of this problem suitable for undergraduates working over a summer. The bacteriophage ? is a classic, well studied virus capable of infecting E. coli, another classic model genetic sytem. We therefore seek to engineer a ? strain targeted to lyse specific subpopulations of E. coli based on their transcriptional profiles. Together, ? and E. coli provide a tractable genetic model for this larger problem, while hopefully providing lessons applicable to more ambitious, future projects.

Training E.coli: “All E.coli ’s are equal, but some E.coli ’s are more equal than others…” (freely adapted from “Animal Farm” by George Orwell) … this is what George Orwell would have written, were he a synthetic biologist. In the E.coli colonies on petri dishes, all bacteria are equal; except for some special ones. Our project is about designing such special E.coli that are “more equal” than the rest: they have the ability to be trained in order to memorize and recognize their environment in the future. Their story will be presented through this wiki …