“…Some authors have reported that gram-negative microorganisms are slightly more sensitive to essential oils when compared to gram-positive [32][33][34][35][36][37][38][39][40][41][42] . The gram-positive and gram-negative microorganisms differ in several aspects other than with respect to the structure of their cellular walls, mainly with regard to the presence of lipoproteins and lipopolysaccharides in gram-negative bacteria that form a barrier to hydrophobic compounds [43,44] .…”