Abstract
Spore germination plays an essential role in the pathogenesis of
-associated food poisoning. Germination is initiated when bacterial spores sense various stimuli, including chemicals and enzymes. A previous study showed that dipicolinic acid (DPA) chelated with calcium (Ca-DPA) significantly stimulated spore germination in
. However, whether Ca
or DPA alone can induce germination is unknown. Therefore, we aimed to evaluate the possible roles of Ca
and other divalent cations present in the spore core, such as Mn
and Mg
, in
spore germination. Our study demonstrated that (i) Ca-DPA, but not DPA alone, induced
spore germination, suggesting that Ca
might play a signaling role; (ii) all tested calcium salts induced spore germination, indicating that Ca
is critical for germination; (iii) the spore-specific divalent cations Mn
and Mg
, but not Zn
, induced spore germination, suggesting that spore core-specific divalent cations are involved in
spore germination; and (iv) endogenous Ca
and Mg
are not required for induction of
spore germination, whereas exogenous and partly endogenous Mn
are required. Collectively, our results suggest that exogenous spore core-specific divalent cation signals are more important than endogenous signals for the induction of spore germination.