M10 Medium: Difference between revisions

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Created page with "== Description == M10 is a medium without rumen fluid for nonselective enumeration and isolation of rumen bacteria [1]. == Recipe == {| class="wikitable" |+ !Component !Percentage in medium<sup>a</sup> |- |Glucose |0.05 |- |Cellobiose |0.05 |- |Soluble Starch |0.05 |- |Minerals (v/v)<sup>b</sup> |3.75 |- |Na<sub>2</sub>S·9H<sub>2</sub>O |0.025 |- |Cystein·HCl·H<sub>2</sub>O |0.025 |- |Resazurin |0.001 |- |Na<sub>2</sub>CO<sub>3</sub> |0.4 |- |Trypticase |0.2 |- |Yeast..."
 
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<sup>a</sup> Weight/ volume unless otherwise indicated.
<sup>a</sup> Weight/ volume unless otherwise indicated.


<sup>b</sup> Except for K<sub>2</sub>HPO<sub>4</sub>, which was prepared separately, the minerals were prepared as a common stock solution. The final mineral concentrations in the medium were as follows: KH<sub>2</sub>PO<sub>4</sub>, 1.3 X 10<sup>-3</sup> M; NaCl, 7.6 X 10<sup>-4</sup> M; (NH)<sub>2</sub>SO<sub>4</sub>, 3.4 X 10<sup>-3</sup> M; K<sub>2</sub>HPO<sub>4</sub>, 1.7 X 10<sup>-3</sup> M; Ca(Cl)<sub>2</sub>, 4.1 X 10<sup>-4</sup> M; MgSO<sub>4</sub>c·7H<sub>2</sub>0, 3.8 X 10<sup>-4</sup> M.
<sup>b</sup> Except for K<sub>2</sub>HPO<sub>4</sub>, which was prepared separately, the minerals were prepared as a common stock solution. The final mineral concentrations in the medium were as follows: KH<sub>2</sub>PO<sub>4</sub>, 1.3 X 10<sup>-3</sup> M; NaCl, 7.6 X 10<sup>-4</sup> M; (NH)<sub>2</sub>SO<sub>4</sub>, 3.4 X 10<sup>-3</sup> M; K<sub>2</sub>HPO<sub>4</sub>, 1.7 X 10<sup>-3</sup> M; Ca(Cl)<sub>2</sub>, 4.1 X 10<sup>-4</sup> M; MgSO<sub>4</sub>·7H<sub>2</sub>0, 3.8 X 10<sup>-4</sup> M.


<sup>c</sup> The volatile fatty acid mixture used was the following: acetic, 17 ml (2.9 X 10<sup>-2</sup> M); propionic, 6ml (8.0 X 10<sup>-</sup><sup>3</sup> M); butyric, 4 ml (4.3 X 10<sup>-</sup><sup>3</sup> M); isobutyric, 1 ml (1.1 X 10<sup>-3</sup> M); n-valeric, isovaleric, and DL-α-methylbutyric, 1 ml each (9 X 10<sup>-4</sup> 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.
<sup>c</sup> The volatile fatty acid mixture used was the following: acetic, 17 ml (2.9 X 10<sup>-2</sup> M); propionic, 6ml (8.0 X 10<sup>-</sup><sup>3</sup> M); butyric, 4 ml (4.3 X 10<sup>-</sup><sup>3</sup> M); isobutyric, 1 ml (1.1 X 10<sup>-3</sup> M); n-valeric, isovaleric, and DL-α-methylbutyric, 1 ml each (9 X 10<sup>-4</sup> 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.
 
== Direction ==
 
Mix all the components in distilled water except Na<sub>2</sub>CO<sub>3</sub> and Cystein·HCl·H<sub>2</sub>O. Boil the medium, then cool it immediately in an ice bath while bubuling with 100% CO<sub>2</sub>. Add appropirate amount of Na<sub>2</sub>CO<sub>3</sub> and  Cystein·HCl·H<sub>2</sub>O, 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.
The final pH of media is 6.7 to 6.8.
 
=== Directions ===
Suspend 38 g of RCM in 1 liter of distilled water. Boil to dissolve solids completely, aliquot, and sterilize by autoclaving at 121 °C for 15 minutes.


== Notes ==
== Notes ==
[[File:Cell pellet formation of Megasphaera elsdenii strain AG22635 in RCM variant.png|thumb|Cell pellet of Megasphaera elsdenii strain AG22635 after a 10-minute 5000 x g centrifuge spin. The culture on the left was grown in commercial RCM. The culture on the right was grown in lab-made RCM without agar.]]
Store bought RCM contains 0.5 g/L agar to mitigate oxygen permeability into the medium. The addition of this agar can have a compounding effect on the formation of [[wikipedia:Extracellular_polymeric_substance|extracellular polymeric substances (EPS)]] in some species like [[Sharpea azabuensis KH1P5|Sharpea azubuensis]] and [[Megasphaera elsdenii T81|Megasphaera elsdeni]]. This EPS generation makes the formation of cell pellets difficult and can affect the procedure of making competent cells. It's recommended to make your RCM "in house" without agar to avoid this complication.
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== Sources ==
== Sources ==


* [https://documents.thermofisher.com/TFS-Assets/MBD/Specification-Sheets/BT-SPEC-0099.pdf ThermoFisher CM0149] (Used by Guss Lab)
[1] Caldwell DR, Bryant MP. 1966. Medium without rumen fluid for nonselective enumeration and isolation of rumen bacteria. Appl Microbiol 14:794–801.

Latest revision as of 17:11, 30 October 2026

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.

Direction

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.