Effects of some mechanical factors on the endospores of Bacillus subtilis.

Knaysi, Georges (Cornell University, Ithaca, N. Y.) and Harold R. Curran. Effects of some mechanical factors on the endospores of Bacillus subtilis. J. Bacteriol. 82:691-694. 1961.-Phase contrast microscopy was used to study incipient spore germination and early growth under conditions involving agitation with a platinum wire loop, sonic oscillation, and freezing and thawing. Treatment resulted in change in optical properties and destruction of a certain proportion of the spores. Up to one-tenth of the spores was destroyed by loop agitation. Sonic oscillation had little apparent effect upon incipient germination (darkening) of the spores, but subsequent development involving growth was stimulated in a considerable proportion. The effect of freezing and thawing upon incipient germination is discussed.