Modificaciones en la respuesta al calor de Bacillus cereus inducidas por la utilización de diferentes lotes del medio de recuperación

The influence of several batches of Nutrient Agar and Plate Count Agar on the heat resistance of Bacillus cereus (ATCC 4342 y 9818) was investigated. The recovery counts were considerably modified by the use of different batches of these media. However, apparent D-values were never affected. Addition of 50 and 100 ppm of calcium to the recovery media improved the effectiveness, except the strain 9818 which when Nutrient Agar was supplemented with 100 ppm of calcium showed a decrease in apparent D-values.