The peptidoglycan layer in Gram-positive bacteria is:
Gram-positive bacteria lack outer membrane but retain an unusually thick peptidoglycan sacculus measuring 20 to 80 nanometers, composed of many layers of glycan strands made of alternating N-acetylglucosamine and N-acetylmuramic acid crosslinked by tetrapeptide side chains containing L-alanine, D-glutamate, meso-diaminopimelic acid or L-lysine, and D-alanine, often further cross-bridged by interpeptide bridges. Embedded within and covalently attached to this mesh are anionic wall teichoic acids, polymers of ribitol or glycerol phosphate linked via phosphodiester bonds, and lipoteichoic acids a
Ref: Silhavy et al., The Bacterial Cell Envelope; Vollmer et al., FEMS Microbiol Rev 2008, Peptidoglycan and Teichoic Acids.