N-acetylglucosaminidase involved in cortex peptidoglycan degradation during germination (PubMed:18835992, PubMed:22343356). Cleaves only partially degraded spore peptidoglycans. Recognizes muramic acid delta-lactam residues specific to spore peptidoglycans (PubMed:22343356). Localizes to the coat or cortex of the endospore. Expressed during sporulation. The LysM domains are involved in substrate recognition and binding to cortical peptidoglycans. They are also involved in directing protein localization. The inactivation of the gene does not affect vegetative growth, spore viability, or the initial stages of germination, including dipicolinic acid release. However, germination of mutant spores is slightly delayed and mutants retain more diaminopimelic acid and N-acetylmuramic acid during germination than wild-type spores. Belongs to the glycosyl hydrolase 18 family. Chitinase class II subfamily.