Sensitization of Bacillus subtilis spores to dry heat and desiccation by pretreatment with oxidizing agents.
OBJECTIVE
To determine if pretreatment with oxidizing agents sensitizes Bacillus subtilis spores to dry heat or desiccation.


METHODS
Bacillus subtilis spores were killed approx. 90% by oxidizing agents, and the sensitivity of treated and untreated spores to dry heat and desiccation was determined. The effects of pyruvate on spore recovery after oxidizing agent pretreatment and then dry heat or desiccation were also determined.


CONCLUSIONS
Spores pretreated with Oxone or hypochlorite were not sensitized to dry heat or freeze-drying. However, hydrogen peroxide or t-butylhydroperoxide pretreatment sensitized spores to dry heat or desiccation, and the desiccation caused mutagenesis in the survivors. Pyruvate increased recovery of spores treated with hydrogen peroxide alone or plus dry heat or desiccation, and with t-butylhydroperoxide and desiccation, but not with t-butylhydroperoxide alone or plus dry heat.


CONCLUSIONS
Pretreatment with peroxides sensitizes bacterial spores to subsequent stress. This finding may suggest improved regimens for spore inactivation.
de Benito Armas
A
A
Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030-3305, USA.
Padula
N L
NL
Setlow
B
B
Setlow
P
P
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects*; D003890:Desiccation; D006358:Hot Temperature; D050296:Microbial Viability; D016877:Oxidants / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D016877:Oxidants