Chitin is the second most plenteous polysaccharide in nature after cellulose, present in cell walls of several fungi, exoskeletons of insects, and crustacean shells. Chitin does not accumulate in the environment due to presence of bacterial chitinases, despite its abundance. These enzymes are able to degrade chitin present in the cell walls of fungi as well as the exoskeletons of insect. They have shown being the potential agents for biological control of the plant diseases caused by various pathogenic fungi and insect pests and thus can be used as an alternative to chemical pesticides.
Chitin mainly helps to form exoskeleton as in arthropods and some species of fungi; in addition chitin in several species is associated with many proteins, which determine whether the exoskeleton will be rigid, soft, or flexible. It also associates with non-protein part such as calcium carbonate that forms the structure in shrimp, crab, and lobsters. Chitin and its related materials have extensive applications in drug delivery: wound healing, dietary fiber, and wastewater treatment. Also, chitin provides protective benefits by forming exoskeleton in arthropods and fungi.
Chitinases are present in plants and act as a part of plant defense mechanism. Chitinase can also be directly used as biopesticides against various fungi and insects that can be an alternative to chemical pesticides.
Chitinases have several field applications. They are attaining prominence in the field of biotechnology applied in waste management, pest control in agriculture, and human health care.