Table 4. β-galactosidase activity obtained using an adapted assay with A. tumefaciens NT1 (pZLR4) as bioreporter and grown in the presence of supernatants from biofilm cultures (1% v/v).

	Miller units	n (%)
Control (YM)	143.5±6.4
Genistein (37 nM)	122.1±25.6
Umbelliferone (62 nM)	131.2±7.2
3-oxo-C6-HSL (5.5 µM)	824.7±21.2
SMH12	717.6±23.6	100
SMH12+genistein (3.7 µM)	843.9±24.6	117*
SVQ648	702.7±28.4	97
SVQ648+genistein (3.7 µM)	745.8±39.2	104
SMH12 (pME6863)	150.2±53.8	21*
SMH12 (pME6863)+genistein (3.7 µM)	152.2±9.71	21*

Data are the mean ± SD of three independent experiments performed in triplicate.

n: percentage of induction of each supernatant with respect to SMH12 without flavonoids, defined as 100%.

Each β-galactosidase activity using biofilm supernatant was individually compared to that obtained in SMH12 without flavonoids by using the Mann-Whitney non-parametrical test. Numbers on the percentage of induction column followed by * are significantly different at the level α = 5%.