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J T WACHSMAN

Publications and source records attributed to J T WACHSMAN.

9 recordsLinked to original sources
PubMed1964

THYMINELESS INDUCTION OF BACTERIOPHAGE IN BACILLUS MEGATERIUM.

Maisch, W. F. (University of Illinois, Urbana), and J. T. Wachsman. Thymineless induction of bacteriophage in Bacillus megaterium. J. Bacteriol. 88:1388-1393. 1964.-Strain KM:T(-)(L) of Bacillus megaterium was obtained by lysogenizing a previously characterized thymine auxotroph of strain KM (KM:T(-)) with a phage suspension from B. megaterium 899a. When strain KM:T(-)(L) is deprived of thymidine in an otherwise sufficient medium, both thymineless death and phage induction occur. The presence of thymidine is required, however, for phage development. When cells are starved for 2 hr, intracellular phage and free phage may be detected approximately 30 and 40 min, respectively, after thymidine addition. Maximal free phage titers were found to vary between 3 x 10(8) and 5 x 10(9) per ml. This represents as much as a 50,000-fold increase in free phage titer over that found during thymidine starvation, and up to a 1,000-fold increase over that found during normal exponential growth.

Bacillus megaterium↗
PubMed1962

Effect of 8-azaguanine on growth and viability of Bacillus megaterium.

Mangalo, R. (University of Illinois, Urbana) and J. T. Wachsman. Effect of 8-azaguanine on growth and viability of Bacillus megaterium. J. Bacteriol. 83:27-34. 1962.-The addition of 8-azaguanine to exponentially growing cells of Bacillus megaterium results in an inhibition of growth after a lag of approximately 30 min. However, 8-azaguanine-2-C(14) is incorporated into the nucleic acids in a linear fashion without a detectable lag. The inhibitory action is reversed by purines and their derivatives, but not by uridine, thymidine, or cytidine. 8-Azaguanine is bactericidal, especially under conditions where growth (ribonucleic acid synthesis) is possible. Growth in the presence of a complete amino acid mixture, either before or during exposure to 8-azaguanine, increases the rate of killing. Chloramphenicol has little or no effect on the bactericidal action of the analogue.

Amino Acids↗
PubMed1962

Use of 8-azaguanine for the isolation of auxotrophic mutants of Bacillus megaterium.

Wachsman, J. T. (University of Illinois, Urbana) and R. Mangalo. Use of 8-azaguanine for the isolation of auxotrophic mutants of Bacillus megaterium. J. Bacteriol. 83:35-37. 1962.-8-Azaguanine is bactericidal for Bacillus megaterium strain KM, primarily under conditions where growth is possible. This analogue has been used to enrich for auxotrophic mutants in ultraviolet-irradiated populations. The survivors were found to contain from 1.6 to 33.0% amino acid auxotrophs and from 19 to 29% pyrimidine nucleoside auxotrophs. Since many different biological systems are sensitive to 8-azaguanine, the use of this analogue to enrich for auxotrophic mutants may have a more general application than techniques currently employed.

Amino Acids↗