Characterization of the putative CYP153A operon regulator AlkR. (A) AlkR is induced by medium- and long-chain n-alkanes and C12-FAME. (B) AlkR can be weakly induced by 1-dodecanol. (C) The addition of 1-dodecanol does not repress dodecane induction. Abbreviations: None, water for induction control; C8 to C18, alkanes with different carbon numbers; C12-FAME, dodecyl methyl ether; C12OH, 1-dodecanol; a.u., arbitrary units.