Appearance (Colour)
Light cream
Appearance (Form)
Free flowing, homogeneous powder
Solubility
25.00 gms/liter
Solubility before autoclaving (Clarity)
Very slightly opalescent
Gel strength
Firm, comparable with 1.5% agar gel
pH (25°C)
7.5 ± 0.2
Prepared Medium Appearance after autoclaving (Clarity)
Very slightly opalescent
Prepared Medium Appearance after autoclaving (Colour)
Light amber
Cultural Response
Inoculate and incubate at 37°C for 18 -4 8 hours
Organism
Escherichia coli ATCC 25922
Inoculum (cfu) 10-100
Growth : Good
Starch hydrolysis : (-ve)
Organism
Staphylococcus aureus ATCC 25923
Inoculum (cfu) 10-100
Growth : Good
Starch hydrolysis : (-ve)
Organism
Streptococcus pyogenes ATCC 19615
Inoculum (cfu) 10-100
Growth : Good
Starch hydrolysis : (-ve)
Organism
Bacillus subtilis ATCC 6633
Inoculum (cfu) 10-100
Growth : Good
Starch hydrolysis : (+ve)
Key
(+) = Starch hydrolysis is indicated by a colourless zone around the colonies after addition of Iodine Reagent.
(-) = A blue or purple zone indicates that the starch has not been hydrolysed. after addition of Iodine Reagent.
Applications
For detection of starch hydrolyzing microorganisms.
Composition
Ingredients
gm/lt.
Agar
12.00
Beef extract (ex. buffalo)
3.00
Soluble starch
10.00
Directions
1. Add 25.00 gm powder to 1.0 liter distilled/purified water and mix thoroughly.
2. Gently heat and bring to boiling.
3. Autoclave at 15 psi pressure at 121°C for 15 minutes.
4. Dispense into sterile petri plates.
