Increase in Bacteriophage and Gelatinase Concentration in Cultures of Bacillus Megatherium

Northrop, John H.

doi:10.1085/jgp.23.1.59

Cited by 16 publications

(8 citation statements)

References 17 publications

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“…The adsorbed phage is lost and the cells which lyse do not form new particles. Thus the phenomenon can be regarded as a case of lysis from without (Krueger and Northrop, 1930;Northrop, 1937Northrop, , 1939Delbrfick, 1940). Virolysin, obtained from lysates of phage-infected cells, or autolysin, from autolysates of uninfected cells, may function as the extracelhlar lysin.…”

Section: Introductionmentioning

confidence: 99%

Lysis From Without of S. Aureus K1 by the Combined Action of Phage and Virolysin

Ralston

Baer

Lieberman

et al. 1957

The Journal of General Physiology

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Lysis from without (LFW) occurs in two steps: (1) sensitization of cells by phage, which renders the cells susceptible to (2) destruction of an essential cell structure by an extracellular lytic enzyme. Virolysin, from phage-infected cells, was used in these studies. Normal cell autolysin is also effective.Evidence is presented that: 1. Neither phage nor lysin alone causes LFW. 2. Sensitization requires phage adsorption. 3. It can be caused by non-infectious particles. This establishes a new biological activity of the particle.4. Heat, U.V., detergents, penicillin, and other damaging agents also sensitize cells. 5. Sensitization involves a non-lethal, reversible reaction. 6. Sensitization by phage prevents vires synthesis. Following adsorption, a cell can undergo sensitization or infection but not simultaneously. When only a few particles are adsorbed, infection can occur; when sufficient particles are adsorbed, sensitization takes place.7. Quantitative aspects of LFW are described. Lysis proceeds logarithmically. The lysis end-point depends upon the phage concentration but is independent of the enzyme concentration.

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Section: Introductionmentioning

confidence: 99%

Lysis From Without of S. Aureus K1 by the Combined Action of Phage and Virolysin

Ralston

Baer

Lieberman

et al. 1957

The Journal of General Physiology

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“…Culture Medium Tryptone broth (Sinsheimer, 1959), or nutrient broth (NB), or yeast extract peptone (YEP) (Northrop, 1939). Sinsheimer (1959).…”

Section: Methodsmentioning

confidence: 99%

Appearance of Virulent Bacteriophages in Lysogenic E. coli Cultures after Prolonged Growth in the Presence of Triethylenemelamine

Northrop

1968

The Journal of General Physiology

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Continuous culture of coli 12X, P22, 600-434, 600-21, and 600-299 in the presence of triethylenemelamine (TEM) results in the appearance of a new virulent virus which attacks the parent culture. N-Methyl-N'-nitro-Nnitrosoguanidine (MNNG) is effective with 600-21 and ultraviolet light with 12X and 600-21. The cultures which produce the virulent virus continue to do so indefinitely in the absence of the mutagen, but are not lysogenic for the virus. Most of the cells in such cultures are resistant to the virus and do not produce any, but there are a few mutant cells sensitive to the virus and the virus multiplies by infection of these sensitive mutants.

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“…It can be assumed that the majority of vegetative bacilli of strain 899 carry phage, since almost all the spores, if not all, contain phage. Although virus-infected, the proportion of lysogenic bacilli undergoing lysis in an actively growing culture is small, in fact so small as to be imperceptible by the usual optometric techniques (Northrop, 1939 Figure 1. Comparative lysis of lysogenic (B. megatherium 899) and nonlysogenic (B, megatherium 337 and B. megatherium 337A) bacilli following cessation of aeration.…”

Section: H J Welshimermentioning

confidence: 99%

Observations on Phage Output and on Anaerobic Lysis of Lysogenic Strains of Bacillus Megatherium

Welshimer

1951

J Bacteriol

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The phenomenon of lysogenicity is an interesting aspect of the bacteriumbacteriophage relationship, for this is an instance of host cells capable of carrying virus through an infinite succession of subcultures, even through cycles of sporulation (den Dooren de Jong, 1930, 1932). Unlike other bacterium-bacteriophage systems, infection of the host does not inevitably terminate in its destruction; indeed cultures of lysogenic bacteria may go unrecognized as being different from uninfected cultures of the same species. This report concerns observations on the phage output of the lysogenic BaciUus megatherium 899 and studies on the potential susceptibility of some lysogenic strains of Bacillus megatherium to lysis. EXPERIMENTAL METHODS AND RESULTS Cultures. The strains of Bacillus megatherium used in this study were as follows: 899, a "naturally" lysogenic strain; 337, a nonlysogenic strain sensitive to the phage produced by B. megatherium 899; 337A, also sensitive to the phage of B. megatherium 899 but consisting of asporogenous bacilli; 7L, an "artificially" lysogenic strain derived by infecting B. megatherium 337 with a phage strain CP, isolated from the filtrate Of B. megatherium 899; 7AL, an "artificially" lysogenic strain derived from B. megatherium 337A following infection with the phage CP.

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Increase in Bacteriophage and Gelatinase Concentration in Cultures of Bacillus Megatherium

Cited by 16 publications

References 17 publications

Lysis From Without of S. Aureus K1 by the Combined Action of Phage and Virolysin

Lysis From Without of S. Aureus K1 by the Combined Action of Phage and Virolysin

Appearance of Virulent Bacteriophages in Lysogenic E. coli Cultures after Prolonged Growth in the Presence of Triethylenemelamine

Observations on Phage Output and on Anaerobic Lysis of Lysogenic Strains of Bacillus Megatherium

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