M10 Medium
Description
M10 is a medium without rumen fluid for nonselective enumeration and isolation of rumen bacteria [1].
Recipe
| Component | Percentage in mediuma |
|---|---|
| Glucose | 0.05 |
| Cellobiose | 0.05 |
| Soluble Starch | 0.05 |
| Minerals (v/v)b | 3.75 |
| Na2S·9H2O | 0.025 |
| Cystein·HCl·H2O | 0.025 |
| Resazurin | 0.001 |
| Na2CO3 | 0.4 |
| Trypticase | 0.2 |
| Yeast extract | 0.05 |
| Volatile fatty acids (v/v)c | 0.31 |
| Hemin | 0.0001 |
a Weight/ volume unless otherwise indicated.
b Except for K2HPO4, which was prepared separately, the minerals were prepared as a common stock solution. The final mineral concentrations in the medium were as follows: KH2PO4, 1.3 X 10-3 M; NaCl, 7.6 X 10-4 M; (NH)2SO4, 3.4 X 10-3 M; K2HPO4, 1.7 X 10-3 M; Ca(Cl)2, 4.1 X 10-4 M; MgSO4·7H20, 3.8 X 10-4 M.
c The volatile fatty acid mixture used was the following: acetic, 17 ml (2.9 X 10-2 M); propionic, 6ml (8.0 X 10-3 M); butyric, 4 ml (4.3 X 10-3 M); isobutyric, 1 ml (1.1 X 10-3 M); n-valeric, isovaleric, and DL-α-methylbutyric, 1 ml each (9 X 10-4 M). The figures in parentheses indicate the final concentration of each acid when 0.31 ml of mixture was placed in a final medium volume of 100 ml.
Method
Mix all the components in distilled water except Na2CO3 and Cystein·HCl·H2O. Boil the medium, then cool it immediately in an ice bath while bubuling with 100% CO2. Add appropirate amount of Na2CO3 and Cystein·HCl·H2O, once the medium is cooled. Adjust th pH to 6.7-6.8 by addition of NaOH. Aliquot the medium, and autoclave at 121 °C for 20 minutes.
Notes
Sources
[1] Caldwell DR, Bryant MP. 1966. Medium without rumen fluid for nonselective enumeration and isolation of rumen bacteria. Appl Microbiol 14:794–801.
