Asundew with a leaf bent around a fly trapped by mucilage
Mucilage is a thick gluey substance produced by nearly allplants and somemicroorganisms. These microorganisms includeprotists which use it for their locomotion, with the direction of their movement always opposite to that of the secretion of mucilage.[1] It is apolarglycoprotein and anexopolysaccharide. Mucilage in plants plays a role in the storage ofwater andfood, seedgermination, and thickening membranes. Cacti (and othersucculents) andflax seeds are especially rich sources of mucilage.[2]
Exopolysaccharides are the most stabilising factor formicroaggregates and are widely distributed insoils. Therefore, exopolysaccharide-producing "soilalgae" play a vital role in theecology of the world's soils. The substance covers the outside of, for example,unicellular orfilamentousgreen algae andcyanobacteria. Amongst the green algae especially, the groupVolvocales are known to produce exopolysaccharides at a certain point in theirlife cycle. It occurs in almost all plants, but usually in small amounts. It is frequently associated with substances liketannins andalkaloids.[3]
Glass container for mucilage, from the first half of the 20th century
Mucilage is edible. It is used inmedicine as it relieves irritation of mucous membranes by forming a protective film. It is known to act as a soluble, or viscous,dietary fiber that thickens the fecal mass, an example being the consumption of fiber supplements containingpsyllium seed husks.[5]
Mucilage mixed with water has been used as aglue, especially for bonding paper items such as labels,postage stamps, and envelope flaps.[7]Differing types and varying strengths of mucilage can also be used for other adhesive applications, including gluing labels to metal cans, wood to china, and leather to pasteboard.[8] During the fermentation ofnattōsoybeans, extracellular enzymes produced by thebacteriumBacillus natto react with soybean sugars to produce mucilage. The amount and viscosity of the mucilage are important nattō characteristics, contributing to nattō's unique taste and smell.
The presence of mucilage in seeds affects important ecological processes in some plant species, such as tolerance of water stress, competition viaallelopathy, or facilitation of germination through attachment to soil particles.[13][14][15] Some authors have also suggested a role of seed mucilage in protectingDNA material fromirradiation damage.[16] The amount of mucilage produced per seed has been shown to vary across thedistribution range of a species, in relation with local environmental conditions of the populations.[17]
^Dawidowsky, Ferdinand (1905).Glue, Gelatine, Animal Charcoal, Phosphorus, Cements, Pastes, and Mucilage. Henry Carey Baird & Co. p. 1.ISBN978-1-113-00611-0.{{cite book}}:ISBN / Date incompatibility (help)
^"Drosera L."Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved16 March 2023.
^Östman, Elisabeth (1911)."Recept på filmjölk, filbunke och långmjölk".Iduns kokbok (in Swedish). Stockholm: Aktiebolaget Ljus, Isaac Marcus' Boktryckeriaktiebolag. p. 161.Archived from the original on 29 October 2008. Retrieved18 July 2007.
^Harper, J. L.; Benton, R. A. (1 January 1966). "The Behaviour of Seeds in Soil: II. The Germination of Seeds on the Surface of a Water Supplying Substrate".Journal of Ecology.54 (1):151–166.Bibcode:1966JEcol..54..151H.doi:10.2307/2257664.JSTOR2257664.
