TABLE 2.

Effect of ethanethiol and ethanedithiol on heat killing of wild-type and α⁻β⁻ spores of B. subtilis^a

Treatment conditionsb	% of spores survivingc
	Wild type (PS832)	α−β− (PS356)
Experiment 1
90°C, no additions	1.0 ± 0.4
90°C, plus ethanethiold	0.5 ± 0.2
80°C, no additions		1.2 ± 0.4
80°C, plus ethanethiold		1.5 ± 0.5
Experiment 2
90°C, no additions	0.3 ± 0.1
90°C, plus ethanedithiold	0.3 ± 0.1
80°C, no additions		2.9 ± 1
80°C, plus ethanedithiold		2.0 ± 1

^aSpores were prepared and cleaned as described in the text and suspended in water in capped tubes with or without 25 mM ethanethiol or ethanedithiol. After incubation overnight at 10°C, tubes were either heated for 30 min or not heated and cooled in ice for 30 min, and samples were plated to determine viable counts. 

^bValues are percentages ± standard deviations and are the averages of quadruplicate determinations in at least two separate experiments. 

^cDifferent preparations of spores were used for experiments 1 and 2, and for the experiment in Table 1. 

^dObtained from the Aldrich Chemical Company.