EFFECT OF HEAT AND PLATING MEDIUM ON SURVIVAL OF ESCHERICHIA COLI AFTER TREATMENT WITH RADIOMIMETIC CHEMICALS

Inactivating and mutagenic effects of 1-methyl-3-nitro-1-nitrosoguanidine on intracellular bacteriophage

1-Methyl-3-nitro-1-nitrosoguanidine (NG) was able to inactivate and mutate adsorbed but not free coliphage T2. Coliphage T4 was as sensitive to NG as T2. When treatment was delayed for 5 min or longer after adsorption of T2, the phage became increasingly refractory to NG inactivation.

Radiomimetic properties of 2-amnipurine in Escherichia coli

Zampieri, Antonio (Palo Alto Medical Research Foundation, Palo Alto, Calif.), and Joseph Greenberg. Radiomimetic properties of 2-aminopurine in Escherichia coli. J. Bacteriol. 91:1773-1774. 1966.-A radioresistant mutant (R(4)) of Escherichia coli strain S was found to be resistant to 2-aminopurine. The composition of the post-treatment plating medium and temperature of incubation did not influence the sensitivity of R(4) to 2-aminopurine. However, strain S was much more sensitive to 2-aminopurine when plated on tryptone-agar than on minimal glucose-salts-agar. Strain S was also more sensitive when the post-treatment incubation was at 37 C than at 45 C. When E. coli strain S was treated with sufficient 2-aminopurine to permit only 10(-5) survivors, 67% of the survivors were resistant to ultraviolet light and to radiomimetic compounds. 2-Aminopurine induced filaments in radiation-sensitive, but not radiation-resistant, strains of E. coli. It is concluded that 2-aminopurine, a base analogue which induces transition mutations, is radiomimetic in several properties.