The effect of chlorine on spores of Clostridium bifermentans, Bacillus subtilis and Bacillus cereus.

The effect of chlorine on the germination, outgrowth, colony formation and structure of spores of Clostridium bifermentans, Bacillus subtilis var. niger and Bacillus cereus was examined. Chlorine decreased heat resistance and slowed or prevented germination and swelling, but spores that did swell were usualy able to elongate to form vegetative cells. Chlorine removed protein from spores, apparently from the coat, and allowed lysozyme to initiate germination. Treatment with other agents that remove spore-coat protein increased the lethal effect of chlorine by as much as 4000-fold, suggesting that coat protein protects spores against chlorine.