The method describes the qualitative determination of sulphite-reducing, spore-forming anaerobes in mineral, spring and table water by means of a single-strength dextrose-iron citrate-sodium sulphite broth (DRCM broth) (according to ASU § 64 LFGB L59.00-4, 1988-05).
Mineral, spring and table waters as well as drinking waters that are to be marketed.
Qualitative detection of sulphite-reducing, spore-forming anaerobes in mineral water, spring water, table water, and other drinking water bottled for distribution to the consumer, by means of membrane filtration and immersion of the filter in single-concentrate dextrose-iron citrate-sodium sulphite broth (DRCM broth).
Note 1: If only the spores of sulphite-reducing anaerobes are to be analysed, the prescribed sample volume must be heated at 75 °C ± 1 °C for 10 minutes in order to inactivate the vegetative cells. Then cool quickly with cold water.
Important: Carry out a comparative test with the same volume of tap water to determine the total heating time required in the water bath.