What about those hydrolases ?

Colisweeper depends largely on processing of molecular signals and generation of visible and distinguishable outputs accordingly. Next to our P_LuxR promoter mutations, which detect ranges of OHHL concentrations, we made use of a reporter system which gives colorimetric responses and additionally provides that the visibility of output is only to be triggered by the player of Colisweeper: A set of orthogonal hydrolases which specifically cleave the chromogenic hydrolase substrates added by the player.
These hydrolases include the Citrobacter alkaline phospohatase, the Bacillus subtilis β-glucuronidase and the Escherichia coli acetylesterase, N-acetyl-β-glucosaminidase and β-galactosidase. To ensure specific enzyme-substrate reactions, we used a triple deletion Escherichia coli strain, lacking aes (acetylesterase), gusA (β-glucuronidase) and nagZ (N-acetyl-β-glucosaminidase).

Beta-galactosidase(LacZ)

Chemical conversion



Colorimetric response in liquid culture

Colorimetric response on LB-Agar

Fig.5: X-Gal on LacZ expressing colony

Fig.6: Beta-green-X-gal on LacZ expressing colony

Alkaline phosphatase(PhoA)

Chemical conversion



Colorimetric response in liquid culture

Colorimetric response on LB-Agar

Fig.2: NPP on PhoA expressing colony

Acetyl esterase(Aes)

Chemical conversion



Colorimetric response in liquid culture

Colorimetric response on LB-Agar

Fig.1: Magenta butyrate on Aes expressing colony

Beta-glucuronidase(GusA)

Chemical conversion



Colorimetric response in liquid culture

Colorimetric response on LB-Agar

Fig.3 Magenta glucuronide on GusA expressing colony

β-N-Acetylglucosaminidase(NagZ)

Chemical conversion



Colorimetric response in liquid culture

Colorimetric response on LB-Agar

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