Brand:
Thermo ScientificTM OxoidTM
Isolate and enumerate wild yeasts encountered in brewing while suppressing pitching yeasts with Thermo Scientific⢠Oxoid⢠Lysine Medium (Dehydrated). This complex, synthetic medium is based on the original formula of Morris & Eddy which utilizes the susceptibility of pitching yeasts to lysine to differentiate it from the wild yeast.
Lysine Medium, Oxoid Composition
| Typical Formula* |
gm/litre
|
| Glucose |
44.5
|
| Potassium dihydrogen phosphate |
1.78
|
| Magnesium sulphate |
0.89
|
| Calcium chloride fused |
0.178
|
| Sodium chloride |
0.089
|
| Adenine |
0.00178
|
| DL-methionine |
0.000891
|
| L-histidine |
0.000891
|
| DL-tryptophane |
0.000891
|
| Boric acid |
0.0000089
|
| Zinc sulphate |
0.0000356
|
| Ammonium molybdate |
0.0000178
|
| Manganese sulphate |
0.0000356
|
| Ferrous sulphate |
0.0002225
|
| Lysine |
1.0
|
| Inositol |
0.02
|
| Calcium pantothenate |
0.002
|
| Aneurine |
0.0004
|
| Pyridoxine |
0.0004
|
| p-aminobenzoic acid |
0.0002
|
| Nicotinic acid |
0.0004
|
| Riboflavin |
0.0002
|
| Biotin |
0.000002
|
| Folic acid |
0.000001
|
| Agar |
17.8
|
| pH (see directions) |
|
Lysine Medium, Oxoid Preparation:
Suspend 6.6g in 100ml distilled water containing 1.0ml Potassium lactate SR0037. Bring to the boil to dissolve completely. Agitate frequently to prevent superheating. Cool to 50°C and add 0.1ml of lactic acid 10% SR0021 to adjust to pH 4.8 ± 0.2. Dispense into Petri dishes and remove surface moisture by drying at 37°C.
Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.