Table 1.

Minimal nutrient requirements for growth of D. radiodurans in the absence and in the presence of gamma irradiation (6,000 rads/h)a

ClassComponentConcn necessary for growth
(I) Without radiation(II) With radiation
BufferPotassium phosphate buffer (pH 7.5 to 8.0)20 mM20 mM
SaltsMagnesium chloride tetrahydrate0.2 mM0.2 mM
Calcium chloride dihydrate0.1 mM0.1 mM
Manganese(II) acetate tetrahydrate5.0 μM5.0 μM
Ammonium molybdate tetrahydrate5.0 μM5.0 μM
Ferrous sulfate heptahydrate5.0 μM5.0 μM
Amino acids l-Histidine25 μg/ml200 μg/ml
l-Cysteine30 μg/ml 30 μg/ml
l-Glutamine500 μg/ml
l-Alanine500 μg/ml
l-Arginine800 μg/ml
l-Asparagine800 μg/ml
Glycine300 μg/ml
l-Leucine500 μg/ml
l-Lysine300 μg/ml
l-Methionine100 μg/ml
l-Proline370 μg/ml
l-Serine300 μg/ml
l-Threonine200 μg/ml
l-Tryptophan200 μg/ml
l-Tyrosine200 μg/ml
l-Valine200 μg/ml
Vitaminsb Nicotinic acid1.0 μg/ml1.0 μg/ml
Carbon source2 mg/ml2 mg/ml
  • a Basal salt medium was autoclaved and then supplemented with sterile preparations of salts, amino acids, and nicotinic acid at the concentrations indicated. For solid medium, 1.5% (wt/vol) Noble agar was added before basal salt medium was autoclaved.

  • b Replacing nicotinic acid with Basal Medium Eagle Vitamin Solution (Gibco BRL) improved growth slightly. For growth in liquid minimal medium, the cells used for inoculation were pregrown on solid minimal medium.