Lab M, producer of microbiological culture media, has introduced a Differential Reinforced Clostridial Medium ISO (DRCM) for the detection and enumeration of the spores of sulphite-reducing anaerobes.
Sulphite-reducing anaerobes, Clostridia spores in particular, can be useful indicators of intermittent and remote faecal contamination.
Widespread in the environment, the spores of these organisms are more resistant than vegetative cells to physical change, chemical change and chlorination, allowing them to survive in water for long periods.
After first treating samples to remove vegetative cells, DRCM is used with the Most Probable Number (MPN) method to determine Clostridia content per volume of sample.
Because of the inclusion of Iron (III) citrate in the DRCM formulation, blackening of the medium indicates sulphite reduction, highlighting the presence of the sulphite-reducing bacteria.
