Figure 6
C4-HSL and 3-oxo-C12-HSL quantification. a) C4-HSL quantification using two E. coli luxCDABE specific C4-HSL biosensors harbored in pSB406 and pSB536. Bioluminescence induced by AHL extracts of PUPa3 corresponding to 7 × 109 cells grown in presence of SIC of tobramycin (0.05 μg/mL) at 37°C was defined as the percentage relative to the same strain without antibiotic (white bar). Each assay was an independent experiment measured in triplicates. +/- represents extract from PUPa3 grown in presence or absence of SIC of tobramycin added to biosensor culture. b) 3-oxo-C12-HSL quantification: the columns represent the 3-oxo-C12-HSL quantification determined by using the biosensor P. putida SM17 (pRSAL220). E represents 5 ml of biosensor culture supplemented with 5 μl ethyl-acetate, +/- addition of 5 μl of AHL extract of PUPa3 (equivalent to 9.2 × 109 cells) grown in presence or absence of SIC of tobramycin (0.05 μg/mL).