Use of [3H]tetrahydrocerulenin to assay condensing enzyme activity in Streptomyces erythreus

Irradiation for a period of 20min reduced the survival of conidia to 20%. The growth of irradiated conidia in the presence of bleomycin, mitomycin C or Esidrex is associated with a 2to 3-fold increase in the frequency of gene convertants, but was not accompanied by an increase in point mutants. When conjdia were grown on cellophane but otherwise treated as before the frequency of gene convertants was increased 8-fold, but induction of point mutants was negligible. This effect was the same for irradiated and unirradiated conidia. The environment created by the cellophane in contact with the medium appears to affect the action of each of the three compounds synergistically.