Advance in the research of peptidoglycan of the bacterial cell wall

Peptidoglycans are constituents of bacterial cell walls. Peptidoglycan is present in most of the Gram-positive bacteria and some of the Gram-negative bacterial. It exhibited various biological activities in the host, especially in immunomodulating. This article summarized the structure, isolation and purification, biological (synthesis), metabolism, functional mechanism and application prospect of peptidoglycan.