Horizontal method for the enumeration of sulfite-reducing bacteria growing under anaerobic conditions
ISO 15213 (2003) method: Sulfite-reducing bacteria
Process control Food and animal feeding stuffs
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1 Quantitative process control with CRM-CP - Use a quantitative reference material (CRM-CP) with a known number of Clostridium perfringens.
- Defrost the material at room temperature for 30 minutes.
- Mix well before use and dilute the material so countable numbers are inoculated on the media (IS("TS")) by spread plate method.
- 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.
- Incubate at (37 ± 1) °C for (24 ± 3) h to (48 ± 2) h.
- Count the colony forming units and register in a control chart.
- The characteristic reaction is: Black colonies.
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2 Quantitative process control with RM-CP veg - Use a quantitative reference material (RM-CP veg) with a known number of Clostridium perfringens.
- Defrost the material at room temperature for 30 minutes.
- Mix well before use and dilute the material so countable numbers are inoculated on the media (IS("TS")) by spread plate method.
- 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.
- Incubate at (37 ± 1) °C for (24 ± 3) h to (48 ± 2) h.
- Count the colony forming units and register in a control chart.
- The characteristic reaction is: Black colonies.
Best Practice
The single strain CRM-CP can be used when only vegetative cells are measured
Best Practice
The single strain RM-CP veg can be used when vegetative cells and or spores are measured
