Native, industrial and fossil chitins

Countless living organisms continuously synthesize and degrade chitin enzymatically, for nutritional, morphogenetic and defensive or aggressive purposes. Chemically modified chitins are important in the light of their biochemical significance in medicine and crop protection; their environmentally friendly behaviour permits industrial exploitation of the huge chitinous biomasses generated by fishing activities and biotechnology. Chitin is promptly metabolized in sediments, and fossil chitin is not frequently encountered.