Chemical Composition: A polysaccharide composed of glucuronic acid. rhamnose and glucose, and O-acetyl moieties. Appearance: Dry, white powder. Solids: 85- 95% Gel Strength: 225 - 500 g/cm2 (media formulated with 0.6 - 0.8% GROVGEL and 0 .10% MgSO4-7H2O)
1. Dissolve the specified quantity of the selected dehydrated base medium (see table below). MgC12-
6H2O and GROVGEL in 1 liter of distilled water.
2. Autoclave the solution for 15 minutes at 121°C, 15 psi
3. Cool the medium to a holding temperature of 60oC after a gentle swirl
4. Dispense the medium into petri dishes or into screw-capped tubes.
NOTE: Other formulations available upon request from MUR & MUR Technical Services.
1. Mix dissolve 2.25 – 2.5 gm GROVGEL and all other components in 1 liter of distilled water.
2. Heat with repeated stirring and boil for 1 minute to dissolve completely.
3. Dispense into test tubes and autoclave for 15 minutes at 121 oC 15 psi.
4. Allow to cool.
GROVGEL gellan gum requires the presence of either monovalent or divalent cations for gelation
GROVGEL gels can be modified by changing the concentration and type of cation in the media Magnesium is the preferred ion for microbiological media applications In most cases it produces a thermally reversible gel. Calcium exerts the most dramatic effect on GROVGEL gel strength, producing gels that do not remelt under normal sterilization conditions. Gels made with a 0.75% concentration of GROVGEL and a 0.1% concentration of MgSO4-7H2O are comparable to gels made with 1.5% agar.
GROVGEL media are wet enough to separate colonies fine enough to prevent migration of organisms within the get. but coarse enough to allow diffusion of macromolecular nutrients.
GROVGEL is chemically inert to most biological growth media additives and is completely compatible with nutrient additives commonly used with agar gels.
GROVGEL gels are optically clear and permit far greater light transmittance than equivalent gels prepared with agar. This makes them suitable for use as an analytical tool.
GROVGEL gellan gum solutions exhibit thermally reversible viscosity changes. Viscosity decreases with increasing temperatures. but returns to its original value upon cooling. GROVGEL has good thermal stability and can withstand normal autoclaving 121oC (15 psi. 15 minutes).
Any components that cannot be autoclaved may be added, as solutions. After autoclaving while the GROVGEL solution is between 55-60oC.
GROVGEL gels have essentially the same shelf-life as agar gels.