Involvement of IMP dehydrogenase activity in induction of sporulation of Bacillus cereus.
IMP dehydrogenase activity of B. cereus increased parallel to cell growth in YE-EMM, where B. cereus did not sporulate. When B. cereus was cultured in a modified G medium, a sporulation medium, the activity reached the highest level at 6 hr and decreased thereafter. After induction of sporulation by nutritional shift down in 1/100 G medium, the enzyme activity decreased to about 5% compared with exponentially growing cells at 1 hr of resuspension. The sporulation rate of B. cereus was over 90% in the modified G medium and 1/100 G medium. Sporulation was strongly inhibited by mycophenolic acid at 1 mM, when the drug was added at 0 and 1 hr of resuspension in 1/100 G medium. Intracellular GTP concentration of B. cereus decreased to the lowest level about 1 hr of resuspension. Although GTP increased to about 50% of the exponentially growing cells at 2 hr of resuspension in control cells, the concentration did not increase in the presence of 1 mM mycophenolic acid.
Miyamoto
T
T
Department of Food Science and Technology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Imamura
M
M
Matsuno
K
K
Kim
S I
SI
Honjoh
K
K
Hatano
S
S
D001409:Bacillus cereus / Q000502:physiology*; D005573:Formycins / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000032:analysis; D007168:IMP Dehydrogenase / Q000502:physiology*; D009173:Mycophenolic Acid / Q000494:pharmacology; D013171:Spores, Bacterial / Q000502:physiology
D005573:Formycins; C034550:formycin; D006160:Guanosine Triphosphate; D007168:IMP Dehydrogenase; D009173:Mycophenolic Acid