Which group of microbes uses peptidoglycan to construct their cell walls?

Bacteria are the only group of microbes that utilize peptidoglycan as a key structural component of their cell walls. Peptidoglycan provides rigidity and shape to bacterial cells, forming a protective layer that is essential for their survival in various environments. This polymer is composed of sugars and amino acids, creating a lattice-like structure that surrounds the cell membrane.

Other groups mentioned, such as viruses, fungi, and protozoa, have different types of cell wall structures or lack them entirely. For instance, viruses do not have cell walls; they are instead made up of genetic material enclosed in a protein coat. Fungi have cell walls composed primarily of chitin, a different polymer altogether. Protozoa may or may not have a cell wall, but if they do, it is generally made of cellulose or other polysaccharides, rather than peptidoglycan. Hence, the unique use of peptidoglycan in cell walls is a defining characteristic of bacteria, differentiating them clearly from these other microbial groups.