Eight gram-negative bacteria are 10,000 times more sensitive to cationic detergents than to anionic detergents.

In liquid culture, eight typical gram-negative bacteria were ca. 10,000-fold more sensitive to cationic detergents than to the anionic detergent sodium dodecyl sulfate. Cetyltrimethylammonium bromide (CTAB) was inhibitory at concentrations ranging from 0.0006% to 0.01%. Four pseudomonads able to form biofilms were ca. 1000-fold more resistant to CTAB on Luria-Bertani agar plates than they were in liquid culture. A lasI mutant of Pseudomonas aeruginosa was only able to tolerate 0.1% CTAB on Luria-Bertani agar plates but could tolerate 5% CTAB when supplemented with homoserine lactone containing culture supernatants.