A. Palop et al., HYDROPEROXIDE INACTIVATION OF ENZYMES WITHIN SPORES OF BACILLUS-MEGATERIUM ATCC19213, FEMS microbiology letters, 142(2-3), 1996, pp. 283-287
Hydroperoxide inactivation of the protoplast enzymes enolase, aldolase
and glucose-6-phosphate dehydrogenase in intact spores of Bacillus me
gaterium ATCC19213 was assessed by first treating the cells with letha
l levels of H2O2, then germinating them in the presence of chloramphen
icol prior to permeabilization and enzyme assays. Glucose-6-phosphate
dehydrogenase proved to be more sensitive to H2O2 than enolase or aldo
lase, in agreement with findings for isolated enzymes. Average D value
s (time for 90% inactivation) for spores treated with 0.50% H2O2 were
173 min for enolase, 67 min for aldolase and 32 min for glucose-6-phos
phate dehydrogenase, compared with a D value of 34 min for spore killi
ng. H2O2 killing of spores was found to be conditional in that recover
ies of survivors were greater on complex medium than on minimal medium
. Overall, it appeared that oxidative inactivation of enzymes may be i
mportant for hydroperoxide killing of spores.