The Effect of Sporulation Medium on Spores of Clostridium bifermentans

Spores of Clostridium bifermentans produced on a Trypticase medium (TRY) and on reinforced clostridial medium (RCM) were compared. RCM-spores contained less dipicolinic acid, outgrew more slowly, were less resistant to hydrogen peroxide and to heat and lost more dipicolinic acid on heating. After treatment with urea/mercaptoethanol both TRY - and RCM-spores germinated with lysozyme, although heating RCM- but not TRY-spores before urea/mercaptoethanol treatment decreased their subsequent germination rate. In thin-section electron micrographs, TRY-spores showed thicker cortices and smaller protoplasts with less visible ribosomes than RCM-spores. The sporulation medium evidently has a marked effect on spore properties. Resistance to heat and to hydrogen peroxide appears to be related to spore structure.