[Effect of thermal shock on resistance of filamentous Bacillus subtilis strain to some hazardous substances].

When grown at 30 degrees C and heat shocked in a liquid medium at 45 degrees C, the filamentous cells of Bacillus subtilis 168 became more sensitive to subsequent killing with N-methyl-N'-nitro-N-nitrosoguanidine and UV light but not with gamma-rays. Certain characteristics (for instance, the increased tolerance to damaging agents at 30 degrees C and the time-dependent changes in the sensitivity to MNNG induced by thermal shock) evidence against direct involvement of repair systems in this phenomenon.