Dichloran Rose Bengal Chloramphenicol Metal Agar

Collect, dilute and prepare samples and volumes as required according to specifications, directives, official standard regulations and/or expected results.

Spread the plates by streaking methodology or by spiral method. Incubate the plates right side up aerobically at 22 ± 2 °C for 48-72 h or up to 7 days.

(Incubation times longer than those mentioned above or different incubation temperatures may be required depending on the sample, on the specifications, etc.)

After incubation, enumerate all the colonies that have appeared on the surface of the agar.

Each laboratory must evaluate the results according to their specifications.

Presumptive isolation of any xerophile must be confirmed by further microbiological and biochemical tests.

Calculate total microbial count per mL of sample by multiplying the average number of colonies per plate by the inverse dilution factor if a diluted sample was streaked. Report results as CFU of xerophiles per mL or g along with incubation time and temperature.

IMPORTANT: PHOTOSENSITIVE PRODUCT. PROTECT FROM LIGHT.

Physical/chemical control

Microbiological control

Inoculate: practical range 100 ± 20 CFU; min. 50 CFU (productivity) / 10⁴-10⁶ (selectivity).

Aerobiosis. Incubation at 25 ± 1 °C, reading at 24-48-72 h to 5 days.

Sterility control

Incubation 48 hours at 30-35 °C and 48 hours at 20-25 °C: NO GROWTH.

Check at 7 days after incubation in same conditions.

• Atlas, R.M., et al. (1993) Handbook of Microbiological Media. CRC Press Inc. London.
• Hocking, A.D., J.I. Pitt (1980) Dichloran-glycerol medium for enumeration of xerophilic fungi from low-moisture food. Appl. Environm. Microbiol. 39:488-492.