Characterization of streptococcal bacteriophage c6A.

Area of Science:

• Microbiology
• Virology
• Molecular Biology

Background:

• Bacteriophages are viruses that infect bacteria.
• Streptococcus lactis is a key bacterium in dairy fermentation.
• Understanding lytic phages is crucial for controlling bacterial populations.

Purpose of the Study:

• To characterize the lytic bacteriophage c6A.
• To investigate its infection dynamics with Streptococcus lactis.
• To analyze the genomic and structural properties of phage c6A.

Main Methods:

• Phage titration to determine plaque-forming units (p.f.u.) per infected cell.
• Electron microscopy for virion structure analysis.
• DNA extraction, sequencing, and restriction enzyme digestion for genomic analysis.

Main Results:

• Phage c6A yielded 124 +/- 8 p.f.u. per infected S. lactis C6 cell.
• A latent period of 25 min at 30°C was observed.
• The virion contains at least 12 polypeptides and a 21.9 kb linear double-stranded DNA genome with specific termini.
• DNA (G+C) content was 36.7%, and restriction mapping revealed unusual cleavage patterns.

Conclusions:

• Bacteriophage c6A is a well-defined lytic phage of Streptococcus lactis.
• Its genomic and structural characteristics provide insights into phage-host interactions.
• The unusual restriction enzyme digestion patterns suggest unique DNA features or modifications.