The Effect of Lysozyme on the Apparent Heat Resistance of Nonproteolytic Type B Clostridium Botulinum

Lysozyme has been shown to increase the recovery of heated spores of type E Clostridium botulinum, thereby increasing the measured heat resistance. This study evaluated the effect of lysozyme on the apparent heat resistance of spores of nonproteolytic type B strains of C. botulinum, which had heat resistances up to 30 times greater than type E strains. Adding lysozyme to the recovery medium increased the apparent heat resistance 16 to 160 times that of values previously established. This increase was comparable to that obtained with type E strain Saratoga (73 times). Lysozyme had no effect on the recovery of heated spores of a proteolytic B strain.