Role of calcium in biphasic germination of Bacillus cereus T spores sensitized to lysozyme.
Biphasic germination induced by inosine in the presence of Ca2+ was examined using Bacillus cereus T spores treated with sodium dodecyl sulfate (SDS) and dithiothreitol (DTT) at pH 10. The first phase of the germination was stimulated by Ca2+ in the concentration-dependent manner, showing the optimal concentration at 0.5-1.0 mM. The second phase appeared to be insensitive to the cation. The optimal temperatures for the first and the second phase were 25 C and 40 C, respectively; the optimal pHs for the two phases were 7-9 and around 7.5, respectively. Heat resistance and dipicolinic acid of the SDS-DTT-treated spores were lost mostly during the first phase. A Ca(2+)-specific chelator, glycoletherdiamine-N,N,N',N'-tetraacetic acid (GEDTA), inhibited the first phase evoked by Ca2+, while it had no inhibitory effect on the second phase. In contrast, the divalent cations examined, except Mg2+ and Sr2+, affected not only the first phase but also the second phase. The order of inhibitory effect on the first phase was Hg2+ > Zn2+ > Ba2+, Co2+, Cu2+ > Mn2+; on the second phase, it was Hg2+ > Cu2+ > Zn2+ > Co2+ > Mn2+ > Ba2+.
Shibata
H
H
Department of Microbial Chemistry, Faculty of Pharmaceutical Sciences, University of Tokushima, Japan.
Adachi
S
S
Hirose
Y
Y
Ike
M
M
Tani
I
I
Hashimoto
T
T
D001409:Bacillus cereus / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002412:Cations / Q000378:metabolism; D004229:Dithiothreitol; D006863:Hydrogen-Ion Concentration; D007288:Inosine / Q000502:physiology; D007700:Kinetics; D009113:Muramidase / Q000502:physiology*; D010848:Picolinic Acids / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate; D013171:Spores, Bacterial; D013696:Temperature
D002412:Cations; D010848:Picolinic Acids; D012967:Sodium Dodecyl Sulfate; D007288:Inosine; D009113:Muramidase; D002118:Calcium; D004229:Dithiothreitol; C004860:dipicolinic acid