Effect of actinomycin D on viability, sporulation and nucleotide pool of Bacillus megaterium.
A transient 7-fold rise of ppGpp concentration, 2-3-fold increase of pppGpp concentration and 50% drop of the concentration of GTP in Bacillus megaterium cells immediately after their transfer to the sporulation medium were observed. Actinomycin D, in concentrations inhibiting RNA synthesis by 95%, blocked the rise of the (p)ppGpp pool and caused an instant several-fold increase of the GTP level. When the cells were exposed to actinomycin D in the sporulation medium for a 1-h period (time 0-1 h, 1-2 h or 2.20-3.20-h), they were able to form colonies on nutrient agar after being kept, in addition for 1-2 h in the sporulation medium free of the antibiotic. The ability of sporulation was, however, markedly limited. The share of cells that could sporulate increased when the irreversible sporulation phase was reached.
Váchová
L
L
Department of Enzyme Engineering, Czechoslovak Academy of Sciences, Prague.
Strnadová
M
M
Kucerová
H
H
Chaloupka
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism*; D001410:Bacillus megaterium / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D003609:Dactinomycin / Q000494:pharmacology*; D006150:Guanine Nucleotides / Q000378:metabolism*; D006158:Guanosine Pentaphosphate / Q000378:metabolism; D006159:Guanosine Tetraphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D013171:Spores, Bacterial
D006150:Guanine Nucleotides; D003609:Dactinomycin; D006159:Guanosine Tetraphosphate; D006158:Guanosine Pentaphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate