Lysozyme hydrolyzes β(1→4) linkages between N-acetyl-muraminic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. The enzyme is used to lyse bacterial cell walls. Gram-positive cells are quite susceptible to this hydrolysis as their cell walls have a high proportion of peptidoglycan. In contrast, Gram-negative bacteria are less susceptible due to the presence of an outer membrane and a lower proportion of peptidoglycan.