Study on interaction between T4 phage and Escherichia coli B by microcalorimetric method

Area of Science:

• Microbiology
• Biophysics
• Molecular Biology

Background:

• Bacteriophages, such as T4 phage, are viruses that infect bacteria.
• Escherichia coli B is a common laboratory strain used in phage research.
• Understanding phage-host interactions is crucial for various biological and biotechnological applications.

Purpose of the Study:

• To quantitatively characterize the process of T4 phage multiplication in Escherichia coli B.
• To investigate the metabolic activity of host cells during phage infection.
• To detect and analyze the phenomenon of lysis inhibition (LIN).

Main Methods:

• Utilized the LKB-2277 Bioactivity Monitor with a stopped-flow method.
• Measured bacterial growth turbidometrically at 37°C.
• Analyzed thermo-curves to derive quantitative parameters (e.g., k(a), P(max), G) and fitted infection-lysis equations to determine the lytic rate constant (k(L)).

Main Results:

• Quantitative parameters characterizing host-phage interactions were obtained and showed regular changes with decreasing multiplicity of infection (MOI).
• Metabolic activity of infected Escherichia coli B cells was found to be more intensive than that of normal, uninfected cells.
• Lysis inhibition (LIN) was detected for the first time using microcalorimetry during T4 phage infection of E. coli B.

Conclusions:

• The study provides quantitative insights into T4 phage multiplication dynamics within Escherichia coli B.
• Infection by T4 phage significantly enhances the metabolic activity of host cells.
• The novel detection of lysis inhibition offers new avenues for exploring phage-host interactions and phage biology.