Exopolysaccharides are the most stabilising factor for microaggregates and are widely distributed in soils. Therefore, exopolysaccharide-producing "soil algae" play a vital role in the ecology of the world's soils. The substance covers the outside of, for example, unicellular or filamentousgreen algae and cyanobacteria. Amongst the green algae especially, the group Volvocales are known to produce exopolysaccharides at a certain point in their life cycle. It occurs in almost all plants, but usually in small amounts. It is frequently associated with substances like tannins and alkaloids.
Glass container for mucilage, from the first half of the 20th century.
Mucilage is edible. It is used in medicine 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 containing Psyllium seed husks.
Mucilage mixed with water has been used as a glue, especially for bonding paper items such as labels, postage stamps, and envelope flaps.
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.
During the fermentation of natt?soybeans, extracellular enzymes produced by the bacteriumBacillus natto react with soybean sugars to produce mucilage. The amount and viscosity of the mucilage are important natt? characteristics, contributing to natt?'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 via allelopathy, or facilitation of germination through attachment to soil particles. Some authors have also suggested a role of seed mucilage in protecting DNA material from irradiation damage. The amount of mucilage produced per seed has been shown to vary across the distribution range of a species, in relation with local environmental conditions of the populations.
^Harper, J. L.; Benton, R. A. (1966-01-01). "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. doi:10.2307/2257664. JSTOR2257664.