R2a agar
From Infogalactic: the planetary knowledge core
R2A agar (Reasoner´s 2A agar) is a culture medium[1] developed to study bacteria which normally inhabit potable water.[2] These bacteria tend to be slow-growing species and would quickly be suppressed by faster-growing species on a richer culture medium.
Since its development in 1979,[3] it has been found to allow the culturing of many other bacteria that will not readily grow on fuller, complex organic media.
Typical Composition (g/l)
Proteose peptone, 0.5
Casamino acids, 0.5
Yeast extract, 0.5
Dextrose, 0.5
Soluble starch, 0.5
Dipotassium phosphate, 0.3
Magnesium sulfate per 7H2O, 0.05
Sodium pyruvate, 0.3
Agar, 15
Final pH 7 ± 0.2 @ 25 °C
