R2a agar

R2A agar is a culture medium developed to study bacteria which normally inhabit potable water. 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, 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

Glucose,          0.5

Soluble starch,   0.5

Dipotassium phosphate,  0.3

Magnesium sulfate 7H2O, 0.05

Sodium pyruvate, 0.3

Agar, 15

Final pH 7.2 ± 0.2 @ 25 °C ' ==