BACILLUS CEREUS GROUP ENRICHMENT MEDIUM. --D. R. Zeigler (unpublished). Nutrient broth (Difco). 8 g. NaCl. 30 g. H2O. 1000 ml. Adjust pH to 6.0, then ...
BACILLUS CEREUS GROUP ENRICHMENT MEDIUM --D. R. Zeigler (unpublished)
Nutrient broth (Difco) NaCl H2O Adjust pH to 6.0, then add: Agar Sterilize by autoclaving; cool to 55°C.
8 g 30 g 1000 ml 15 g
Add, from filter-sterilized aqueous stocks: Penicillin G Cycloserine Polymyxin Lysozyme
2 15 1 1
mg mg mg mg
Suspend sample in sterile water by vortexing. Allow solid material (soil, food particles) to settle for 5 minutes. Prepare a dilution series in sterile water. Incubate dilutions at 65°C for 15 min. Spread 100 μl of each dilution on an agar plate and incubate 48 hours at 30°C. Virtually every colony will be Bacillus cereus or a related organism. When soil samples are plated, about 1-2% of the isolates will form parasporal crystals and can tentatively be identified as B. thuringiensis.
