Js. Lee et al., THE INDUCTION OF OXIDATIVE-ENZYMES IN STREPTOMYCES-COELICOLOR UPON HYDROGEN-PEROXIDE TREATMENT, Journal of General Microbiology, 139, 1993, pp. 1013-1018
Streptomyces coelicolor (Mulier) became resistant to killing by hydrog
en peroxide (H2O2) when pretreated with non-lethal concentrations of H
2O2. When rapidly growing cells were pretreated with 100 muM-H2O2, the
y became 7-10-fold more resistant to 20 mm-H2O2 than were naive cells.
Activities of several oxidative defense enzymes were measured in cell
s treated with 100 muM-H2O2 in either exponential or stationary phase
growth. The specific activity of catalase in crude extracts of cells p
retreated in either phase increased about 40%. Peroxidase activity, in
cell extracts and culture supernatants, respectively, of cells treate
d in the stationary growth phase increased two times and four times. G
lucose-6-phosphate dehydrogenase increased by 60 % at the exponential
growth phase. Glutathione reductase increased 80 % after treatment in
the exponential phase and 4-fold in the stationary growth phase. Howev
er, superoxide dismutase activity decreased by 70%. Two mutants resist
ant to H2O2 were isolated after mutagenesis of spores with N-methyl-N'
-nitro-N-nitrosoguanidine. In addition to a dramatic increase in the s
urvival rate in 20 mm-H2O2, both mutants exhibited increased activitie
s of all the above enzymes except superoxide dismutase. The pleiotropi
c phenotype of the mutants suggests that there exists a global regulat
ion of oxidative response in S. coelicolor.