Direct microscopy of Bacillus endospore germination in soil microcosms

Antagonistic endospore-forming Bacillus spp. offer a large potential as see d inoculants for control of soil-borne pathogens. In the soil, however, ino culated Bacillus endospores may remain dormant without germination, and pla nt protection can therefore be inefficient and unpredictable. A method base d on direct fluorescence microscopy in soil microcosms was used to determin e whether low-cost organic additives incorporated into seed coating materia l could stimulate endospore germination. Complex organic additives supporte d a high level of endospore germination of the fungal antagonist Paenibacil lus polymyxa CM5-5. Skim milk is a low-cost additive that may be incorporat ed into seed coating material for efficient induction of Bacillus endospore germination in soil.