Fig. 4
From: Development of a novel heterologous β-lactam-specific whole-cell biosensor in Bacillus subtilis
Disk diffusion assay of biosensors tested with six β-lactams and two controls. The six β-lactam antibiotics shown here are penicillin (PEN, 50 μg/ml), ampicillin (AMP, 50 μg/ml), cefalexin (LEX, 10 μg/ml), cefoxitin (FOX, 200 μg/ml), carbenicillin (CAR, 100 μg/ml) and cefoperazone (CFP, 200 μg/ml). White light pictures indicate the positions of the disks on the plate. The corresponding images from luminescence detection are displayed underneath. The first two image pairs on the left show the detection of β-lactams by Biosensor 1 and Biosensor 1 in the ΔpenP strain (see Fig. 1c (1), strains TMB3641 and TMB3713). In contrast, the two image pairs on the right demonstrate sensing of β-lactams by the improved Biosensor 2 and Biosensor 2 in the ΔpenP strain (see Fig. 1c (2), strains TMB5608 and TMB5611). Representative images of triplicates are shown. To view the full dataset including all control strains see Supplement 1, Figure S1, S2a, S2b and S3