Differential scanning calorimetric observations concerning the activation mechanism of spores of Phycomyces blakesleeanus.

Spores of Phycomyces were scanned in a Differential Scanning Calorimeter. The spectrum obtained was clearly influenced by previous activation of spores by heat or by acetate.When spores were allowed to return to dormancy the original spectrum of dormant spores was restored. The high temperature at which the difference in the spectrum between activated and dormant spores was found points to a protein denaturation. It is suggested therefore that the activation of spores is obtained through a conformational change of a protein.