ABSTRACT
Synthetic biology employs an engineering approach to design, model, construct, test and characterize BWBs (Fig. 8.2). A few interesting cases of BWBs are shown below:
An evolved riboswitch that is responsive to the herbicide atrazine was used to create a translation-based whole cell biosensor that could sense the presence of atrazine, move to the site of the contamination, and then degrade the toxin. The riboswitch was selected from a randomized library and placed in control of the translation of the bacterial chemotaxis protein CheZ. Therefore, cells were only able to activate chemotaxis in response to atrazine and would migrate to areas of high atrazine concentration. The same cells were given the ability to express an enzyme which converts atrazine to a lower toxicity compound. Thus, the whole cell biosensor was programmed to ”seek and destroy” the contaminant (Sinha et al. 2010).
