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Main sol. 105

Internal Solution-ID: S181

Compound Amount Unit Conc. [g/L] Conc. [mM]
Glucose 100 g 100 555.062
Yeast extract 10 g 10 -
CaCO3 20 g 20 199.82
Distilled water 1000 ml - -
Agar , for solid medium 15 g/l 15 44.599
1 Adjust pH to 6.8.
2 20 g calcium carbonate in the medium serves as a buffer. The calcium carbonate will settle in agar plates before the agar has set, producing an opaque layer in the bottom. As the strain grows and acid is produced this will react with the calcium carbonate, causing it to dissolve and form zones of clearing immediately below the colonies. In liquid culture the calcium carbonate also forms a sediment that clears as acid is produced.