Further characterization of the outer membrane ofSerratia marcescens and an oxacilline-sensitive mutant: Surface carbohydrates and outer membrane lipid composition

Whole cells and isolated outer membranes ofSerratia marcescens and an oxacilline-sensitive mutant could be agglutinated only with concanavalin A and wheat germ agglutinin. Different amounts of carbohydrates were accessible to the lectins in the two strains, and different amounts of carbohydrate seemed to be exposed at the outer cell surface and the inner side of the outer membrane. The fatty acid composition of the isolated outer membrane revealed small but significant quantitative difference. The increased sensitivity towards various antibacterial agents was thought to be the result of an altered hydrophobic-hydrophilic interaction of the outer membrane components.