Mutants of Bacillus cereus strain T that produce thermoresistant spores lacking dipicolinate and have low levels of calcium

Abstract

Mutants of Bacillus cereus strain T that produce thermoresistant spores which lack dipicolinic acid and have low levels of calcium and manganese have been isolated. The thermoresistant dipicolinate-less spores lose thermoresistance upon storage in distilled water and do not germinate in any liquid medium tested. All spores germinated and produced colonies on G medium agar. It is suggested that calcium and dipicolinic acid are not required for the acquisition of thermoresistance in bacterial endospores but that they are essential to the maintenance of the thermorésistant state and are required for normal germination.