Gellan Gummi Chemische Eigenschaften,Einsatz,Produktion Methoden
Beschreibung
Gellan gum is a kind of anionic polysaccharide produced through the submerged fermentation of the bacterium Sphingomonas elodea. It is soluble in water. It is a polymer with tetrascharide being the repeating unit; the tetrascharide consists of two residues of D-glucose and one of each residue of L-rhamnose and D-glucuronic acid. It can be used as a gelling, texturizing and suspension hydrocolloid. It is a suitable agar substitute which can be supplemented to various kinds of growth media for microbes, especially thermophilic microorganisms because of its resistance to relatively high temperature (120 degree). It can also be used as gelling agent in plant cell culture on Petri dishes. It can also be used as a food additive, e.g. it can be used in plant based milks to keep plant protein suspended in the milk.
Chemische Eigenschaften
A high molecular weight polysaccharide gum produced by a pureculture
fermentation of a carbohydrate with Pseudomonas elodea,
and purified by recovery with isopropyl alcohol, dried, and milled.
It is a heteropolysaccharide comprising a tetrasaccharide repeating
unit of one rhamnose, one glucuronic acid, and two glucose units.
The glucuronic acid is neutralized to mixed potassium, sodium,
calcium, and magnesium salts. It may contain acyl (glyceryl and
acetyl) groups as the O-glycosidically linked ester. It occurs as an
off-white powder that is soluble in hot or cold deionized water.
Verwenden
gellan gum is used as a gelling agent, thickener, and stabilizer in cosmetic preparations.
Allgemeine Beschreibung
Typical working concentration: 1.5-2.5 g/L in plant tissue culture media; up to 10 g/L in microbiological media. Phytagel
? requires the presence of cations (especially divalent) for gelling to occur. Concentrations of calcium and magnesium contained in most plant tissue culture media are typically sufficient for gelation. Low-salt media formulations, especially those used in microbiological applications, may require supplementation with additional calcium or magnesium salts (e.g., CaCl
2 or MgSO
4) or higher concentrations of Phytagel.
Einzelnachweise
https://en.wikipedia.org/wiki/Gellan_gum
http://www1.lsbu.ac.uk/water/gellan.html
Gellan Gummi Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
