A previous study concluded that FadD positively regulates hilA expression in the absence of external LCFAs by an unknown FadR-independent mechanism .
The authors suggested that fatty acid and/or their derivatives , activated by FadD , may act as intracellular signals to regulate hilA expression , it has also been demonstrated that LCUFAs , present in the bacterial growth medium , exert a repressive action on the PhoP/PhoQ system activity .
The authors suggested that fatty acid and/or their derivatives , activated by FadD , may act as intracellular signals to regulate hilA expression , it has also been demonstrated that long chain unsaturated free fatty-acids , present in the bacterial growth medium , exert a repressive action on the PhoP/PhoQ system activity .