The mutagenic effect of ultraviolet radiation and nitrous acid on Mycobacterium phlei

ArticleinFolia Microbiologica 11(3):163-8 · February 1966with8 Reads
Impact Factor: 1.00 · DOI: 10.1007/BF02901427 · Source: PubMed

    Abstract

    Lethal and mutagenic effects of nitrous acid and UV radiation onMycobacterium phlei were studied Three auxotrophic strains of the PA strain ofMycobacterium phlei were obtained: ala-, his-, and gly- (ser-) INHr Bods of the his- strain grown in liquid media are longer to filamentous as compared with cells of the prototrophic PA strain grown in the
    same media, whereas cells of the gly- (ser-) INHr mutant are shorter to coccobacillary. Cells of the ala- strain are characterized by their various length from normal to coccobacillary. The auxotrophic strains obtained differ from
    each other by a frequency of spontaneous reversions to prototrophy. The his- strain is the most stable, a frequency of spontaneous reversions to prototrophy being 10-9. The gly- (ser-) INHr strain reverts spontaneously to prototrophy with a frequency of 10-8 to 10-7. The ala- strain spontaneously reverting with a frequency of 10-5 is the most labile. The auxotrophic mutants obtained do not differ from the original prototrophic strain in the other properties
    studied.

    A change in a frequency of INH and STM-resistant mutants was also studied. It was found that under the influence of UV radiation
    a frequency of INH-resistant mutants increases 43 to 80 fold as compared with a frequency of spontaneous mutations, this latter
    being about 2.6 × 10-6. No substantial increase in a frequency of STM-resistant mutants was found using UV irradiation under the given experimental
    conditions; their spontaneous frequency equals to 9.0 × 10-9 to 2.0 X 10-8.