Lysogenic Versus Lytic Cycle of Phage Multiplication

Bertani, G.

doi:10.1101/sqb.1953.018.01.014

Cited by 70 publications

(41 citation statements)

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“…; this effect can be produced even at a comparatively late stage (20 min.) in the latent period (Bertani, 1953). With the Escherichia coli strain K12-A system studied by Lieb (1953), though raising the temperature from 37" to 46" appeared to promote the lytic rather than the lysogenic response, decreasing the temperature did not favour lysogeny.…”

Section: B a Fry And F Grosmentioning

confidence: 99%

“…Whether analogies should be sought between the effect of the T phages and of A phage on the metabolism of E. coli is, however, doubtful, since there appears to be a t least one fundamental difference between these two types of virus. The phage coats of the T viruses can themselves kill cells (Herriott, 1951;French & Siminovitch, 1955), whereas such a lethal effect has not been demonstrated with phage coats of either wild type or virulent mutants of h (Weigle, quoted by Bertani, 1958).…”

Section: B a Fry And F Grosmentioning

confidence: 99%

“…It is well known that environmental changes can greatly affect the type of response to be elicited from infected cells (cf. Bertani, 1958), and it is feasible that manipulations involved in plating the bacteria in the response test may bring about such changes. Even if there was a small percentage of cells in which phage was maturing, it is possible that the experimental techniques were not sensitive enough to detect net synthesis on such a small scale.…”

Section: B a Fry And F Grosmentioning

confidence: 99%

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The Metabolic Activities of Escherichia coli during the Establishment of Lysogeny

Fry

Gros

1959

Journal of General Microbiology

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SUMMARY: Escherichia coti strain K112 was infected with h phage (multiplicity of input 20 particles/cell) in O-O~M-M~SO,, and 91 yo infected cells gave the lysogenic response. When the infected cells were transferred to a complete amino acid medium containing l4C-~~-pheny1alanine and a non-utilizable inducer for /3-galactosidaseY the net synthesis of protein and nucleic acids did not begin until after 100-120 min. During this period there was no induced synthesis of P-galactosidase (though the enzyme was readily developed in uninfected cells) and there was no increase in turbidity of the culture or in viable cell count. The synthesis of protein and nucleic acids began in uninfected cells immediately they were placed in the complete medium, turbidity increased from the start and the viable count after 30 min. This suggested that during lysogenization the infecting phage temporarily halts most if not all of the synthetic activities of the cell and thus forms an environment in which the phage genome can become attached to the bacterial chromosome and establish the prophage state.The biochemical changes which occur after infection in a cell which is to become lysogenic have not been studied before in any detail. Whilst much attention has been given to the biochemical effects of infection of Escherichia coli by the T phages, only a few experiments (cf. Lwoff, 1954-5) have been concerned with the effect of temperate phage on the metabolism of the host cell. The purpose of the present work was to attempt to study what determines the choice between the lytic and the lysogenic response, since the factors controlling this decision are not understood. At least in some bacteria, lysogeny is favoured by a high multiplicity of infection (Boyd, 1951), and after infection, changes in the environment, e.g. changes in temperature (Bertani & Nice, 1954), or the presence of substances which prevent protein synthesis (Lwoff, Kaplan & Ritz, 1954;Christensen, 1957) can alter the type of response. Conditions have been established for infecting virtually all the cells of a suspension of E. coti with h phage, and thus obtaining a population in which more than 90 yo of the infected cells give the lysogenic response. Some of the biochemical activities of these cells were examined and are reported here. A summary of these results has been given previously (Fry & Gros, 1958). METHODSThe organism, Escherichia coli strain K l l 2 , the preparation of washed cell suspensions and stock suspension of phage lambda the composition of nutrient broth, the detection of response of infected cells and the determination of viable counts have been described previously (Fry, 1959).

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Section: B a Fry And F Grosmentioning

confidence: 99%

Section: B a Fry And F Grosmentioning

confidence: 99%

Section: B a Fry And F Grosmentioning

confidence: 99%

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The Metabolic Activities of Escherichia coli during the Establishment of Lysogeny

Fry

Gros

1959

Journal of General Microbiology

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“…It seemed that in two instances the addition of another prophage rendered the bacteria less inducible. One explanation that was considered was the substitution of the original prophage by the second phage (Bertani, 1953). Unfortunately, the NCTC phages used always made plaques on the indicators which were suitable for testing the phages carried by the NCTC staphylococci.…”

Section: Discussionmentioning

confidence: 99%

The Induction of Bacteriophage in Staphylococci

Gorrill

Gray

1956

Journal of General Microbiology

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“…Bertani (1953) and Jacob (1954) were able to obtain approximate calculations of the number of prophages/lysogenic bacterium. Both workers (Bertani with lysogenic Shigella dysenteriae and Jacob with lysogenic Pseudomonas aeruginosa) concluded that the number of prophages/bacterium was close to the number of nuclei.…”

Section: J F Whitjield and R K Appleyardmentioning

confidence: 99%