INFLUENCE OF SPORULATION TEMPERATURE ON THE HEAT-RESISTANCE OF A STRAIN OF BACILLUS-LICHENIFORMIS (SPANISH TYPE CULTURE COLLECTION-4523)

The influence of the sporulation temperature on the heat resistance of a strain of Bacillus licheniformis isolated during a routine control for sterility of canned vegetables, has been studied. Heat resistance of this strain at any temperature of treatment increased with increasi ng sporulation temperature. Spores sporulated at 52 degrees C were 10- fold more heat resistant than those sporulated at 30 degrees C. The ma gnitude of this influence was not constant along the range of sporulat ion temperatures tested (30, 37, 44 and 52 degrees C). No statistical significance (P less than or equal to 0.05) differences were detected among z values obtained with spores sporulated at different temperatur es. This increase of heat resistance at higher sporulation temperature s could account for the frequent failures of sterilization processes o f canned vegetables, during hot seasons in warmer regions. (C) 1995 Ac ademic Press Limited.