Glucanase

Enzymes that break down glucans

Glucans are important structural compounds in the cell walls of plants and fungi. Chemically, glucans are a type of carbohydrate. They consist of the same basic building blocks (monosaccharides) as starches, but the units are arranged differently.

Many microorganisms produce glucanases, which enable them to digest glucans and use them as a source of nutrients. Industrially, bacteria are used to produce glucanases on a large scale for use in applications such as beer brewing. Glucanase supplements help beer yeasts break down glucans in barley, which can often block filters. (In Germany, glucanase additives are not permitted because they do not conform to the German Beer Purity Act.)

Genes for certain glucanases (usually b-1,3-glucanases) have been transferred to plants to enable them to degrade the glucans in disease-causing fungi. Researchers are developing grapes, wheat, and barley with glucanase-conferred fungus resistance.

Genetically modified barley with a novel gene for glucanase can help improve the quality of animal feed. Some animals lack the glucanases needed to break down long chain glucanes present in barley cell walls. Therefore, poultry raised with barley without added glucanase remain small.