Information processing

The agar minefield consists of colonies in a hexagonal grid with mine and non-mine colonies. We have two bacterial strains: Firstly the mine strain which provides the sender cells and secondly the non-mine strain which provides the receiver cells. The sender cells secret AHL that diffuses through the agar. The player pipets substrate on a colony, which leads to a change in the color of the colony. This gives the player information to logically carry out the next move in the game. The colonies remain white until any substrate is added. The left and the right click of the mouse is simulated with the addition of the multi-substrate mix and the single substrate respectively.

The sender colony secretes the signaling molecule 3-oxo-N-hexanoyl-L-homoserine lactone (AHL)by LuxI activation, that diffuses through the agar to the surrounding cells. In the receiver cells, the signaling molecule forms a complex with the inactive LuxR to activate it. By using different sensitive P_LuxR promoters the AHL input concentration is translated into different outputs. In our case different hydrolases. Within minutes after the addition of substrate a change in color indicates the identity of the played colony and number of surrounding mine colonies.

Figure 1:Information processing from secreted signaling molecule to colorimetric response. The signal diffuses through the agar from sender cells (light blue) to receiver cells (dark blue).The non-mine colonies are designed to distinguish between different concentrations of AHL and translate this information into expression of different hydrolases. The expression is driven by different P_LuxR promoters that show different AHL sensitivities and serve as high pass filters. After an incubation time of 12 hours the player pipets a substrate on the colony. The hydrolase converts the substrate into a colored product which is visible by eye

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