FIG. 4.

Induction of the ean box-lacZ transcriptional fusion in E. coli DH5α by different AHL compounds. E. coli DH5α carrying pJN105ER and pQF50ER was grown in the LB medium with various synthetic AHLs. After 15 h of incubation, the β-galactosidase activity was measured. Arabinose was used for the induction of expression of EanR at a concentration of 0.4%. Ara⁻ indicates activity without arabinose and AHL. AHL⁻ indicates the result with 0.4% arabinose and without AHL. The results were reproduced in three repeated experiments, and error bars indicate standard deviations.