N-acetylmuramyl-L-alanine amidase involved in innate immunity by degrading bacterial peptidoglycans (PGN). Probably plays a scavenger role by digesting biologically active PGN into biologically inactive fragments. Has no direct bacteriolytic activity (By similarity). Hydrolyzes the link between N-acetylmuramoyl residues and L-amino acid residues in certain cell-wall glycopeptides. Not expressed in adults. Belongs to the N-acetylmuramoyl-L-alanine amidase 2 family.