ISO 15213 (2003) method: Sulfite-reducing bacteria

Process control Food and animal feeding stuffs

Horizontal method for the enumeration of sulfite-reducing bacteria growing under anaerobic conditions

  • 1 Quantitative process control with CRM-CP

  • Black colonies. The characteristic reaction of  on IS(
    Characteristic reaction: Black colonies.

    Best Practice

    The single strain CRM-CP can be used when only vegetative cells are measured

    1. Use a quantitative reference material (CRM-CP) with a known number of Clostridium perfringens.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use and dilute the material so countable numbers are inoculated on the media (IS("TS")) by spread plate method.
    4. Best results are obtained when a practicable range of 80 cfu to 120 cfu per plate with a minimum number of 50 cfu per plate is used.
    5. Incubate at (37 ± 1) °C for (24 ± 3) h to (48 ± 2) h.
    6. Count the colony forming units and register in a control chart.
    7. The characteristic reaction is: Black colonies.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number
    Single-strain reference material Clostridium perfringens 00007
    The Biosisto reference material in this table is used in the best practice for Quantitative process control according ISO 17025.
  • 2 Quantitative process control with RM-CP veg

  • Black colonies. The characteristic reaction of  on IS(
    Characteristic reaction: Black colonies.

    Best Practice

    The single strain RM-CP veg can be used when vegetative cells and or spores are measured

    1. Use a quantitative reference material (RM-CP veg) with a known number of Clostridium perfringens.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use and dilute the material so countable numbers are inoculated on the media (IS("TS")) by spread plate method.
    4. Best results are obtained when a practicable range of 80 cfu to 120 cfu per plate with a minimum number of 50 cfu per plate is used.
    5. Incubate at (37 ± 1) °C for (24 ± 3) h to (48 ± 2) h.
    6. Count the colony forming units and register in a control chart.
    7. The characteristic reaction is: Black colonies.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number
    Single-strain reference material Clostridium perfringens 00007
    The Biosisto reference material in this table is used in the best practice for Quantitative process control according ISO 17025.