Figure 2.

Peptidoglycan recycling and muropeptide release. PG cleaving enzymes digest the sacculi delivering PG fragments to the periplasm, which can be either released to the environment or transported into the cytoplasm through PG transporters. Once in the cytosol, PG fragments might enter the recycling pathway to finally be reincorporated into the newly polymerized PG mesh or used as an own-energy source by the cell. Part of PG-turnover products is released to the environment, where are detected by other cells and can act as signaling molecules. EM: extracellular matrix.