Fig. 5
From: Regulation of heterologous subtilin production in Bacillus subtilis W168
Spot-on-lawn assay revealed the production of bioactive subtilin in B. subtilis W168. A B. subtilis W168 PliaI-lux (TMB1617) strain containing the subtilin-sensitive promoter PliaI fused to the lux reporter was used as a detector (“lawn”) for subtilin production. PliaI is controlled by the TCS LiaRS encoded in the liaIHGFSR operon of B. subtilis W168. In response to subtilin, LiaRK is activated through “damage-sensing” and induces PliaI, and thus expression of the luciferase cassette (luxABCDE), which can be measured under a bioluminescence imaging device. B Application schematic of “spots” on “lawn”. C The time course of subtilin production by luminescence measurement. Luminescence was measured every 2 h up to 20 h and subsequently in longer intervals up to 48 h. The bright circles in contrast to the background around the “spot” position indicate the induced luminescence production by subtilin. Blue and red arrows on the plate at the 6th hour mark the positive control (B. subtilis ATCC6633), and B. subtilis W168 strain carrying spa-locus and abrB mutation (TMB3044), respectively. The pictures are representatives for triplicates of measurements