Evaluation of Microbiological Methods of Analysis for Natural Mineral Waters, Part 5: Detection of Sulphite-Reducing Anaerobes — Collaborative Trial

Ministry ofAgriculture, Fisheries and Food, Central Science Laboratory, Food Science Laboratory, Norwich Research Park, Colney, Norwich NR4 7UQ, UK T’he results of a collaborative trial of two methods .fbr the detection o;f sporulated sulphite-reducing anaerobes (SRA) in naturaL mineral y)ater dre repofted. Twenty-sisc UK laboratories participoted in the trial to volidate liquid enrichmenl and membrane fihration procedures prescribed by the Intemational Organisotion for Standardisation for use with potoble waters. The results from this trial indicate that the liquid enrichment procedure is the better method for detection of sulphite-reducing onaerobes in natural mineral woter. Where colony counts are desirable, the membrane ./iltration procedure is useJul when used with tryptose sulphite agar. Data from the triol also demonstrated that the posteurisatton lredtment giyen to samples prior to exdmination inaclivated all vegetcttive cells of the autochthonous .flora in the naturol ntineral water.