| ≥1 piece |
gellan gum can be used as an alternative to agar for microbiological media, and as a bacterial growth media. It is also ideal medium for plant tissue cultivation. It is particularly useful for the culture of thermophilic microorganisms, as the gels are thermostable and can withstand prolonged incubations at high temperatures. In addition, acceptable gel strengths can be obtained using gellan gum at a lower level than agar, and spreader colonies do not become too large. In these microbiological media applications, the high purity of gellan gum and the water-like clarity of the gels are distinct additional advantages.
In plant tissue culture, gellan gum offers a promising alternative to agar because of its purity. Gellan gum used at one-fifth the agar use level, resists contamination by moulds, is easily washed from the plant tissue for transplanting, and allows clear observation of root and tissue development. It is extremely effective at low use levels and forms solid gels at concentrations as low as 0.1%. These are prepared by adding an electrolyte (e.g., a salt, an acid or an anionic surfactant) to a hot gellan solution and then cooling.