cen:proj:32851

Isolation and enumeration of enterococci in sludges - Part 1: membrane filtration onto selective agars cen:proj:32851

Scope

This draft standard method specifies a membrane filtration procedure for the quantitative analysis, by culture of individual colonies on selective agar, of enterococci species in sewage sludge samples.
This method is of particular use if determination of treatment efficiency is required as outlined in the revision of Directive 86/278/EEC (3rd draft, CEN/TC 308-doc 525).
The method has a limit of detection of approximately 10 cfu/g wet weight, dependent of the solids content which at high concentrations (>20% (w/v)) can block the filtration of the sample volume through the membrane if not diluted prior to filtration. Therefore if the sludge sample has or is expected to have high solids content or the numbers present are expected to be lower than the detection limit this method may not be suitable.