Characterization of Bacillus pumilus E601 spores after single sublethal gamma irradiation treatments.

Eighteen survivor strains of Bacillus pumilus E601 have been isolated after single sublethal irradiation treatments with 60Co. Primary isolation was based on the loss of motility and pellicle formation. However, with subsequent subcultivation, eight isolates reverted back to the standard of exhibiting motility and pellicle formation. Characteristics of the isolates include alterations in space radiation resistance and in the amino acid requirements for spore germination and outgrowth. Other alterations in cultural and physiological characteristics were found. Three of the isolates were asporogenous.