Iron Sulphite Agar

Iron Sulphite Agar is recommended for the detection of thermophilic anaerobic organisms causing sulphide spoilage in food. This medium is a modification of Cameron Sulphite Agar developed by the National Canners Association of America. Sulphite-reducing bacteria usually produce black colonies as a result of the reduction of sulphite to sulphide, which reacts with the iron (III) salt. The blackening reaction is only presumptive evidence of clostridial growth. Confirmation test must be carried out for identification.