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Published on: October 14, 2011
Evolution of Lactococcus lactis phages within a cheese factory
Geneviève M Rousseau1, Sylvain Moineau
1Département de Biochimie et de Microbiologie, Groupe de Recherche en Ecologie Buccale, Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, Québec G1V 0A6, Canada.
Applied and Environmental Microbiology
|June 23, 2009
Summary
Six lactococcal phages from the 936 group were sequenced, revealing genome similarities and a core genome. One phage strain persisted in a cheese factory for over a year.
Area of Science:
- Microbiology
- Genomics
- Virology
Background:
- Lactococcal phages are critical for the dairy industry, impacting cheese production.
- The 936 group of phages infects industrial Lactococcus lactis strains.
Purpose of the Study:
- To sequence and compare the genomes of six lactococcal phages from the 936 group.
- To investigate phage survival and evolution within a cheese factory environment.
- To identify a core genome for 936 group lactococcal phages.
Main Methods:
- Whole-genome sequencing of six double-stranded DNA lactococcal phages.
- Isolation of phages from whey samples over a 9-year period.
- Bioinformatic analysis including open reading frame prediction and comparative genomics.
- Proteomic analysis using nano-high-performance liquid chromatography-tandem mass spectrometry.
Main Results:
- Genome sequencing revealed lengths from 28,144 to 32,182 bp, coding for 51-55 open reading frames.
- Identical phage genomes (CB14 and GR7) isolated 14 months apart confirmed long-term survival in a cheese plant.
- Comparative genomics indicated that newer phages (CB19, CB20) evolved from older isolates (CB13, CB14/GR7).
- A conserved 11-nucleotide 3' overhang cos site was identified in five phage genomes.
Conclusions:
- Lactococcal phages exhibit genomic diversity within the 936 group.
- Phages can maintain viability in industrial settings for extended periods.
- A core genome for 936 group lactococcal phages was defined, aiding in understanding their evolution and relationships.
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