1887

Abstract

Surmmary

Conditions necessary for the production of thymineless mutants in Gramnegative bacteria by aminopterin treatment were examined. Although and Proteus strains were readily made ‘thymineless’ (i.e. requiring added thymine) no such mutants were obtained with the majority of Aerobacter strains. However, two methods which produced thymineless mutants in all the Aerobacter strains were found; these were: treatment with alkaline EDTA before, or temperature shift down during, incubation with aminopterin. In every case where temperature shift alone resulted in the production of thymineless mutants more were found when it was used in conjunction with EDTA pretreatment. It was also found that the phase and size of inoculum, the method used to sterilize aminopterin and the concentration of thymine in the plating media had profound effects on the production and detection of thymineless mutants.

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/content/journal/micro/10.1099/00221287-47-1-131
1967-04-01
2024-04-23
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References

  1. Barner H. E., Cohen S. S. 1954; The induction of thymine synthesis by T2 infection of a thymine requiring mutant of Escherichia coli. J. Bact. 68:80
    [Google Scholar]
  2. Clowes R. C., Moody E. E. M., Pritchard R. H. 1965; The elimination of extrachromosomal elements in thymineless strains of Escherichia coli k12. Genet.Res. 6:147
    [Google Scholar]
  3. Coughlin C. A., Adelberg E. A. 1956; Bacterial mutation induced by thymine starvation. Nature, Lond. 178:531
    [Google Scholar]
  4. Davis B. D., Mingioli E. S. 1950; Mutants of Escherichia coli requiring methionine or vitamin B 12. J. Bact. 60:17
    [Google Scholar]
  5. Hakala M. T. 1965; On the role of drug penetration in amethopterin resistance of sarcoma-180 cells in vitro. Biochim.biophys. Acta 102:198
    [Google Scholar]
  6. Hamilton-Miller J. M. T., Smith J. T., Knox R. 1965; Interaction of cephaloridine with penicillinase-producing Gram-negative bacteria. Nature, Lond. 208:235
    [Google Scholar]
  7. Korn D., Weissbach A. 1962; Thymineless induction in Escherichia coli k12 (A). Biochim.biophys. Acta 61:775
    [Google Scholar]
  8. Leive L. 1965; A nonspecific increase in permeability in Escherichia coli produced by EDTA. Proc. natn.Acad. Sci., U.S.A. 53:745
    [Google Scholar]
  9. Okada T., Yanagisawa K., Ryan F. J. 1961; A method for securing thymineless mutants from strains of E. coli. Z. VererbLehre 92:403
    [Google Scholar]
  10. Pritchard R. H., Lark K. G. 1964; Induction of replication by thymine starvation at the chromosome origin in Escherichia coli. J. molec.Biol. 9:288
    [Google Scholar]
  11. Sicard N. 1961; Microbial physiology. Role of macromolecular synthesis on the viability of Escherichia coli 15 t-and E. coli 15 t-h-. C. r. hebd.Seanc. Soc. Biol., Paris 252:617
    [Google Scholar]
  12. Smith J. T., Hamilton-Miller J. M. T. 1963; Differences between penicillinases from Gram-positive and Gram-negative bacteria. Nature, Lond. 197:976
    [Google Scholar]
  13. Watanabe T., Fukasawa T. 1961; Episome-mediated transfer of drug resistance in Entero-bacteriaceae. II. Elimination of resistance factors with acridine dyes. J. Bact. 81:679
    [Google Scholar]
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