Natural fiber exoskeletons of insects and arthropods. In shells and exoskeletons, the chitin fibers contribute to their hierarchical structure. In nature, pure chitin (100% acetylation) does not exist. It instead exists as a copolymer with chitin's deacetylated derivative, chitosan. When the acetylized composition of the copolymer is over 50% acetylated it is chitin. This copolymer of chitin and chitosan is a random or block copolymer. Chitosan is a deacetylated derivative of chitin. When the acetylized composition of the copolymer is below 50% it is chitosan. Chitosan is a semicrystalline “polymer of β-(1-4)-2-amino-2-deoxy-D-glucose”. One difference between chitin and chitosan is that chitosan is
Xylanase Xylanase Xylanase (, "endo-(1->4)-beta-xylan 4-xylanohydrolase", "endo-1,4-xylanase", "endo-1,4-beta-xylanase", "beta-1,4-xylanase", "endo-1,4-beta-D-xylanase", "1,4-beta-xylan xylanohydrolase", "beta-xylanase", "beta-1,4-xylan xylanohydrolase", "beta-D-xylanase") is the name given to a class of enzymes which degrade the linear polysaccharide beta-1,4-xylan into xylose, thus breaking down hemicellulose, one of the major components of plant cell walls. As such, it plays a major role in micro-organisms thriving on plant sources for the degradation of plant matter into usable nutrients. Xylanases are produced by fungi, bacteria, yeast, marine algae, protozoans, snails, crustaceans, insect, seeds, etc., (mammals do not produce xylanases). However, the principal commercial source of xylanases is filamentous fungi. Commercial applications for