Heat Studies on a Thermophilic Bacteriophage.

The Influence of Inorganic Ions on the Heat Stability of a Thermophilic Bacteriophage

“…In the present investigation it was found that the heat stability of the thermophilic phage PhBl is not a stable characteristic, but one that is dependent on the composition of the surrounding medium. The observation that this phage is far more heat stable in tryptone broth than in tris buffer is in accordance with an existing report (White, Georgi and Militzer 1955) that thermophilic bacteriophages suspended in phosphate buffer or distilled water are more heat sensitive than phages in broth or gelatin. Furthermore, the results obtained in the present study show that the presence of calcium and magnesium ions in the suspension fluid stabilizes phage PhBl against heat inactivation while ,sodium and potassium ions in comparable concentrations have no significant effect.…”

“…Similar results have been obtained with other mesophilic bacteriophages. White, Georgi andMilitzer (1954, 1955) studied heat inactivation of a thermophilic phage with an optimum temperature for lytic activity at 65"C. It was found that phages suspended in phosphate buffer or in distilled water were more sensitive to temperatures between 75 and 100°C than phages in broth or gelatin.…”

A Bacteriophage Infecting a Thermophilic Bacterium

“…infecting thermophilic bacteria have been isolated by WHITE, GEORGI and MILITZER (1,2) and later by ONODERA (3). The study of the phages is of special interest because of their thermostability in themselves and of their reactivity with the host thermophilic bacteria at high temperatures.…”

“…However, the basic characteristics of these phages have not yet been fully investigated owing to the difficulties in the assay method which seem to be partly due to slow adsorption of the phages to host cells (1,2,3) and partly due to the temperature sensitivity of the host bacteria (4).…”

Production and Purification of the Thermophilic Bacteriophage TP-84

“…Like the mesophilic phages, the thermophilic ones can be subdivided into two main groups: (i) virulent thermophilic phages (2-7, 10,12,13,16,18,19,27,28) and (ii) temperate phages (7, 17, 20-23, 25, 26). Unique in their extreme thermal stability (6,10,12,13,16,19,20,25,27,28), the thermophilic phages have attracted the attention of many investigators. Our interest in the thermophilic phage TP-84 derives from the assumption that thermophilic phages may represent the simplest form of thermophilic organisms and thus the mechanism(s) for their remarkable thermostability might be easier to elucidate.…”