Peptidoglycans are found in large quantities in cell wall of the following microorganism:

The peptidoglycan layer is much thicker in gram-positive than in gram-negative bacteria. Comparison of Cell Walls of Gram-Positive and Gram-Negative Bacteria: Component Gram-Positive Cells Gram-Negative Cells Peptidoglycan Thicker; multilayer Thinner; single layer Teichoic acids Present Absent Lipopolysaccharide (endotoxin) Absent Present Ref: Levinson W. (2012). Chapter 2. Structure of Bacterial Cells. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e.