the plate was overlaid with molten 0.5 %
LB agar containing the biosensor strain C. violaceum
VIR07 using a sprayer. After the plate was incubated at
30 C for 24 h, the position of any violet pigmentation
formed by the biosensor on the plate was compared with
the positions of the spots for the N-octanoyl homoserine
lactone (C8-HSL) and N-hexanoyl homoserine lactone
(C6-HSL) standards