Related Experiment Video

Updated: Sep 6, 2026

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi
09:01

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

Published on: September 28, 2022

The adsorption of bacteriophage phi-X174 to its host

R FUJIMURA, P KAESBERG

    Biophysical Journal
    |November 1, 1962
    PubMed

    Insights

    The bacteriophage phiX174 binds irreversibly to E. coli C cells and cell walls, with optimal adsorption occurring under specific pH and calcium chloride conditions. This irreversible adsorption is crucial for phage infection and DNA release.

    Area of Science:

    • Microbiology
    • Molecular Biology
    • Biophysics

    Background:

    • Bacteriophages are viruses that infect bacteria.
    • Understanding phage-host interactions is crucial for phage therapy and molecular biology.
    • Escherichia coli (E. coli) is a model organism for studying bacterial physiology and phage interactions.

    Purpose of the Study:

    • To investigate the adsorption kinetics of bacteriophage phiX174 (φX174) to E. coli C cells and isolated cell walls.
    • To determine the influence of pH and divalent ions on phage adsorption.
    • To elucidate the mechanism and efficiency of φX174 adsorption to its host.

    Main Methods:

    • Assaying for unadsorbed plaque-forming units to quantify adsorption.
    • Systematically varying pH and calcium chloride (CaCl2) concentrations.
    • Measuring adsorption rates and rate constants.

    Main Results:

    • Irreversible adsorption of φX174 to E. coli C is dependent on pH and divalent ion concentration.
    • Maximum irreversible adsorption was observed in 0.1 M CaCl2 at 36°C.
    • Under optimal conditions, diffusion is not rate-limiting, suggesting a low encounter efficiency (rate constant: 1.0 x 10^-10 ml/sec).
    • No significant reversible adsorption was detected under optimal conditions.

    Conclusions:

    • A specific receptor site for φX174 exists on the mucocomplex portion of the E. coli cell wall.
    • Irreversible adsorption to live cells leads to infection, while adsorption to isolated cell walls results in DNA release.
    • The findings provide insights into the initial stages of phage-host recognition and binding.
    Keywords:
    COLIPHAGES

    More Related Videos

    Following Cell-fate in E. coli After Infection by Phage Lambda06:10

    Following Cell-fate in E. coli After Infection by Phage Lambda

    Published on: October 14, 2011

    Bacteriophage Removal from Infected Salmonella Cultures07:19

    Bacteriophage Removal from Infected Salmonella Cultures

    Published on: June 28, 2024

    Related Concept Videos

    DNA Bacteriophages01:26

    DNA Bacteriophages

    Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
    Lytic Cycle of Bacteriophages01:30

    Lytic Cycle of Bacteriophages

    Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...
    Bacteriophages of the Human Virome01:23

    Bacteriophages of the Human Virome

    Bacteriophages are found throughout the human body. They may even outnumber eukaryotic viruses, forming an important and dynamic component of the human virome. Indeed, phages represent the most abundant viral entities, with densities in the gut reaching up to 10⁹ particles per gram of fecal matter, and many belonging to orders such as Caudovirales and Microviridae, while a substantial proportion remains unclassified as viral “dark matter.”Lysogeny and Genetic ExchangeIn the gut, bacteriophages...
    Viral Replication: Lytic Cycle01:20

    Viral Replication: Lytic Cycle

    Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
    Lysogenic Cycle of Bacteriophages00:43

    Lysogenic Cycle of Bacteriophages

    In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
    Viral Replication: Lysogenic Cycle01:16

    Viral Replication: Lysogenic Cycle

    The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects its...