| The extent of spore activation was compared between protoxin crystal-forming strains of Bacillus thuringiensis subspecies kurstaki and Bacillus cereus and acrystalliferous strains of B. thuringiensis kurstaki and B. cereus. Crystal-forming strains of both species germinated better after incubation in alkaline pH than they did at neutral pH, and also their germination rates were greater than the acrystal-liferous strains incubated in alkaline pH. This indicates that the dissolution of the protoxin crystal by alkaline pH plays a key role in activation of these spores by alkaline pH. |
