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Live-Cell Imaging of the Life Cycle of Bacterial Predator Bdellovibrio bacteriovorus using Time-Lapse Fluorescence Microscopy
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Characterization of Bdellovibrio bacteriovorus bacteriophage MAC-1

R C Roberts1, M A Keefer, R S Ranu

  • 1Department of Microbiology, Colorado State University, Fort Collins 80523.

Journal of General Microbiology
|November 1, 1987
PubMed

Insights

The bacteriophage MAC-1, which infects Bdellovibrio bacteriovorus, possesses a single-stranded DNA genome. This circular DNA molecule has a mass of 1.58 MDa and exists in two replicative forms.

Area of Science:

  • Microbiology
  • Virology
  • Molecular Biology

Background:

  • Bdellovibrio bacteriovorus is a predatory bacterium that preys on other Gram-negative bacteria.
  • Bacteriophages are viruses that infect bacteria and are crucial in microbial ecology and evolution.

Purpose of the Study:

  • To characterize the bacteriophage MAC-1, a specific predator of Bdellovibrio bacteriovorus.
  • To determine the nature and structure of the bacteriophage MAC-1's genetic material.

Main Methods:

  • Phage purification using precipitation and CsCl density gradient centrifugation.
  • Nucleic acid analysis including DNase/RNase digestion, S1 nuclease hydrolysis, and acridine orange staining.
  • Molecular weight determination via agarose gel electrophoresis and electron microscopy.
  • Identification of replicative forms using Southern blot analysis.

Main Results:

  • Bacteriophage MAC-1 was purified and characterized with a density of 1.363 g cm-3 and sedimentation coefficient of 94S.
  • The phage genome was confirmed to be DNA, exhibiting properties consistent with single-stranded DNA.
  • The single-stranded DNA genome is circular, with a molecular mass of 1.58 MDa.
  • Two replicative forms, RF1 (supercoiled) and RF2 (circular), were identified in infected cells.

Conclusions:

  • Bacteriophage MAC-1 harbors a single-stranded, circular DNA genome.
  • The characterization provides insights into the replication and lifecycle of this specific bacteriophage.
  • This study contributes to the understanding of phage-host interactions within the Bdellovibrio bacteriovorus system.

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