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Isolation and preliminary characterization of bacteriophage phi-mu-4
Abstract:
Shafia, Fred (University of Nebraska, Lincoln), and T. L. Thompson. Isolation and preliminary characterization of bacteriophage phimu-4. J. Bacteriol. 87:999-1002. 1964.-Bacteriophage phimu-4 was isolated from lysogenic Bacillus stearothermophilus NU strain 4, and was propagated in strain 10 of the same species. The phage was extremely host-specific. One of the 23 strains of thermophiles screened for susceptibility supported phage replication. Plaque-forming efficiency of phimu-4 depended on the agar medium employed and the temperature of incubation. Generally, media which resulted in restricted growth of the host cells on agar plates were most satisfactory for plaque formation. A latent period of 35 min was terminated in cell lysis and release of about 175 plaque-forming units (PFU) per infected cell. The phage particles, propagated in cells cultured in Trypticase (BBL)-yeast extract-dextrose-calcium chloride broth, were routinely removed from the lysate by 0.6 ammonium sulfate saturation in the cold. Phage purification was by ultracentrifugation followed by sucrose density-gradient. The phage particles appeared spherical, in electron micrographs. Particle size determination by electron micrographs indicated a diameter of less than 100 A.
Insights
This study isolated and characterized bacteriophage phimu-4 from Bacillus stearothermophilus. The phage exhibited extreme host specificity and its plaque formation depended on media and incubation temperature.
Area of Science:
- Microbiology
- Virology
- Bacteriology
Background:
- Lysogenic Bacillus stearothermophilus strains can harbor bacteriophages.
- Characterizing bacteriophages is crucial for understanding microbial interactions and phage biology.
Purpose of the Study:
- To isolate and perform preliminary characterization of bacteriophage phimu-4.
- To investigate the host specificity and plaque-forming efficiency of phimu-4.
Main Methods:
- Isolation of bacteriophage phimu-4 from a lysogenic Bacillus stearothermophilus strain.
- Propagation and plaque assays on various thermophilic strains.
- Electron microscopy for particle morphology and size determination.
Main Results:
- Bacteriophage phimu-4 was isolated and propagated in Bacillus stearothermophilus strain 10.
- The phage demonstrated extreme host specificity, with only one of 23 thermophilic strains supporting replication.
- Plaque formation efficiency was influenced by agar medium composition and incubation temperature.
- A latent period of 35 minutes resulted in approximately 175 plaque-forming units (PFU) per infected cell.
- Electron microscopy revealed spherical phage particles with a diameter less than 100 Angstroms.
Conclusions:
- Bacteriophage phimu-4 is a highly host-specific phage of Bacillus stearothermophilus.
- Environmental factors like media and temperature significantly impact phage plaque formation.
- Preliminary characterization provides foundational data for further research into this bacteriophage.