Xylanase

Function

Xylanases belong to the pentosanases, a group of enzymes that break down components of the cell wall matrix of plants (fibre).

• Xylanases break down xylan (also known as "wood gum") - a woody, gummy, mucous substance that accompanies the cellulose present in all plants. Wheat, for example, has a high content of xylan.
  Xylanes belong to the group of pentosanes (broken down by pentosanases. These again belong to the hemicelluloses (broken down by hemicellulases).

• Arabinofuranosidase is a special pentosanase which can break down various side chains of xylan molecules.

Application

Xylanases are usually used in conjunction with various other specific enzymes: 

• mainly as a baking enzyme to improve dough qualities (workability, stability) and to optimize the product (stabilizing of crust and volume) see also: baking mixtures.

• in the production of liquor and in the alcohol industry (xylanases unlock the mucilaginous substances in grain to utilize them for fermentation).

• in the manufacture of fruit juices and beverages.

Further applications:

• Feed additives
  These enzymes contribute to a better digestion of plant-derived feed by liberating the xylanes contained in plants.

• Starch production in textile and paper industry

Gene technology

Increasingly, the production of xylanases is performed with the aid of genetically modified micro-organisms. These genetically optimized organisms are predominantly cultures of fungi (Aspergillus and Trichoderma species), but also include some bacteria (Bacillus).

• In Europe alone, there are eight preparations of xylanases available that are produced with the aid of genetically modified micro-organisms. In several cases, these are preparations of combinations with other enzymes (e.g. glucanases, amylases).

• To date, several xylanase preparations that are manufactured with the aid of gene technology has been assessed by the European Food Safety Authority (EFSA) as a feed additive.

Labelling: labelling of enzymes in regard to their production using GM microorganisms is generally not foreseen in the European Union.