Has antibacterial activity against the Gram-negative bacterium E.coli. No antibacterial activity detected against the Gram-negative bacterium V.vulnificus. Hydrolysis of (1->4)-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrins. Optimum pH is 7.5-8.5. Highest levels of expression detected in the digestive glands. Lower levels in the mantle, labial palps, gills and style-midgut sac, and lowest levels detected in the hemocytes. Not detected in the gonads. Belongs to the glycosyl hydrolase 22 family. Type-I lysozyme subfamily.