Related Experiment Video
Updated: May 26, 2026
13:28
Single-cell Analysis of Bacillus subtilis Biofilms Using Fluorescence Microscopy and Flow Cytometry
Published on: February 15, 2012
First steps of bacteriophage SPP1 entry into Bacillus subtilis
Lina Jakutytė1, Rudi Lurz, Catarina Baptista
1Unité de Virologie Moléculaire et Structurale, CNRS UPR3296 and IFR 115, Bâtiment 14B, CNRS, 91198 Gif-sur-Yvette, France.
Virology
|December 14, 2011
Summary
Bacteriophage SPP1 rapidly depolarizes the Bacillus subtilis cytoplasmic membrane upon infection, a process dependent on receptor YueB and calcium ion concentrations. This study models the early stages of SPP1 viral infection.
Area of Science:
- Microbiology
- Virology
- Molecular Biology
Background:
- Understanding viral genome transfer is crucial for controlling viral infections.
- Bacteriophages are viruses that infect bacteria, offering insights into microbial dynamics.
- The cytoplasmic membrane's permeability changes are key indicators of early infection events.
Purpose of the Study:
- To investigate the initial steps of bacteriophage SPP1 infection in Bacillus subtilis.
- To characterize the role of the cytoplasmic membrane and specific host factors in SPP1 entry.
- To elucidate the mechanism of genome transfer and its dependence on environmental factors like calcium.
Main Methods:
- Monitoring cytoplasmic membrane (CM) permeability changes during SPP1 infection.
- Comparing CM depolarization kinetics of SPP1 with other bacteriophages (ϕ29, SP01).
- Investigating the influence of phage input, receptor YueB concentration, and Ca(2+) on infection dynamics.
Main Results:
- SPP1 induces faster CM depolarization in Bacillus subtilis compared to podovirus ϕ29 and myovirus SP01.
- SPP1-mediated depolarization requires interaction with the YueB receptor and is modulated by phage concentration and YueB levels.
- Sub-millimolar Ca(2+) is essential for reversible phage binding and triggering depolarization, while millimolar Ca(2+) is needed for DNA delivery.
Conclusions:
- Bacteriophage SPP1 employs a distinct mechanism for initiating infection in Bacillus subtilis, characterized by rapid CM depolarization.
- The YueB receptor and specific calcium ion concentrations play critical, distinct roles in SPP1 binding, membrane perturbation, and genome translocation.
- A model for the early events of SPP1 infection has been developed, highlighting the importance of membrane interactions and ion concentrations.
Related Concept Videos
01:30Lytic 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...
01:26DNA 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...
01:20Viral 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...
00:43Lysogenic 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...
01:10Intracellular Movement of Viruses and Bacteria
Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a virus that...
00:50What are Viruses?
Overview