TABLE 1.

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

Treatment conditions	% of spores survivingb
	Wild type (PS832)	α−β− (PS356)
90°C, aerobic	2.9 ± 0.4
90°C, anaerobic	3.0 ± 0.4
80°C, aerobic		1.0 ± 0.3
80°C, anaerobic		1.2 ± 0.3

^aSpores were prepared and cleaned as described in the text. Spores were suspended in vials under either aerobic or anaerobic conditions as described in the text. Both types of vials were incubated overnight at 10°C, during which time anaerobiosis was achieved in the anaerobic vials. The aerobic vials were then sealed without evacuation, and vials were either heated for 30 min or not heated, and were cooled on ice for ∼30 min. The vials were opened, and viable spores were determined as described in the text. 

^bValues are the averages of duplicate determinations in three separate experiments ± the standard deviations.