ABSTRACTSpores of the putrefactive anaerobe (P.A.) 3679 are widely used in inoculated pack studies designed to evaluate the adequacy of heat processes for low acid foods. For this purpose, it is essential to have the ability to repeatedly grow large amounts (>106) of test spores with comparable heat resistance. Beef heart infusion broth fortified with 1.0 tryptone, 1.0 gelatin, 0.05 glucose, 0.4 dibasic Potassium phosphate, 0.3 sodium citrate, and either 0.5 isoelectric casein or 1.5 skim milk powder, in the presence of beef heart particles was found to be dependable for producing>109heat resistant spores/liter medium when incubated 2 wk at 30°C followed by 1 wk at 20°C. With the beef heart debris either remaining or absent after two washing, the heat resistance of the spores did not change during 1 yr of storage at 4
展开▼
