Major secreted chitinase involved in the degradation of chitin, a component of the cell walls of fungi and exoskeletal elements of some animals (including worms and arthropods). Plays a role in the morphogenesis and autolysis. Has also significant antifungal activity against various fungal species. Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1->4)-beta-linkages in chitin and chitodextrins. Optimum pH is 5.5-6.5. Expression is increased at the beginning of the stationary phase of growth and reaches maximum in the early autolytic phase of growth. Impairs autolysis. Belongs to the glycosyl hydrolase 18 family. Chitinase class V subfamily.