Fig. 1.

E. coli-based whole-cell biosensor XL1-LUX induction by SA. a Representation of chromosomally integrated luxCDABE in Acinetobacter sp. ADPWH_lux (Huang et al. 2005) and pLUX reporter cassette. b Selection of E. coli XL1-LUX transformants on LC plate supplemented with SA. The E. coli transformant selected for our experiments is indicated by the arrow. Scale bar = 1 cm. c Relative luminescence values from XL1-LUX grown in liquid medium with different concentrations of SA, incubated at different temperatures. Luminescence values of uninduced cells (0 µM SA) incubated at room temperature (22 °C) were taken as 1. Error bars represent the mean ± SE (n = 3). d Luminescence images on X-ray film of XL1-LUX streaked onto solid medium containing different concentrations of SA