Fig. 2
From: Engineering probiotics as living diagnostics and therapeutics for improving human health
Engineering probiotic strain for the inhibition of Salmonella infection. The tetrathionate sensing system and Microcin H47 (Mcch47) production system were introduced into E. coli Nissle 1917. The ttr operon (ttrRSBCA) encodes tetrathionate reductase and the mch operon (mchAXIBCDEF) encodes Mcch47. During the course of Salmonella infection, tetrathionate was generated in the inflamed gut. In the presence of tetrathionate, the promoter PttrBCA was activated by the tetrathionate sensor histidine kinase TtrS and the response regulator TtrR. The transcription of the mch operon was initiated to produce Microcin H47 for the inhibition of Salmonella