title: Phage Biodiversity in Artisanal Cheese Wheys Reflects the Complexity of the Fermentation Process.
abstract: Dairy fermentations constitute a perfect "breeding ground" for bacteriophages infecting starter cultures, particularly strains ofLactococcus lactis.In modern fermentations, these phages typically belong to one of three groups, i.e., the 936, P335, and c2 phage groups. Traditional production methods present fewer chemical and physical barriers to phage proliferation compared to modern production systems, while the starter cultures used are typically complex, variable, and undefined. In the current study, a variety of cheese whey, animal-derived rennet, and vat swab samples from artisanal cheeses produced in Sicily were analysed for the presence of lactococcal phages to assess phage diversity in such environments. The complete genomes of 18 representative phage isolates were sequenced, allowing the identification of 10 lactococcal 949 group phages, six P087 group phages, and two members of the 936 group phages. The genetic diversity of these isolates was examined using phylogenetic analysis as well as a focused analysis of the receptor binding proteins, which dictate specific interactions with the host-encoded receptor. Thermal treatments at 63 °C and 83 °C indicate that the 949 phages are particularly sensitive to thermal treatments, followed by the P087 and 936 isolates, which were shown to be much less sensitive to such treatments. This difference may explain the relatively low frequency of isolation of the so-called "rare" 949 and P087 group phages in modern fermentations.
authors.affiliation: School of Microbiology, University College Cork, T12 YT20 Cork, Ireland. j.mahony@ucc.ie.|Alimentary Pharmabiotic Centre, University College Cork, T12 YT20 Cork, Ireland. j.mahony@ucc.ie.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Mahony
authors.affiliation: School of Microbiology, University College Cork, T12 YT20 Cork, Ireland. angelo.moscarelli@gmail.com.|Department of Agricultural and Forest Science, University of Palermo, 90128 Palermo, Italy. angelo.moscarelli@gmail.com.
authors.forename: Angelo
authors.initials: A
authors.lastname: Moscarelli
authors.affiliation: School of Microbiology, University College Cork, T12 YT20 Cork, Ireland. p.r.kelleher@umail.ucc.ie.
authors.forename: Philip
authors.initials: P
authors.lastname: Kelleher
authors.affiliation: Laboratory of Probiogenomics, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy. gabriele.lugli@genprobio.com.
authors.forename: Gabriele A
authors.initials: GA
authors.lastname: Lugli
authors.affiliation: Laboratory of Probiogenomics, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy. marco.ventura@unipr.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Ventura
authors.affiliation: Department of Agricultural and Forest Science, University of Palermo, 90128 Palermo, Italy. luca.settanni@unipa.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Settanni
authors.affiliation: School of Microbiology, University College Cork, T12 YT20 Cork, Ireland. d.vansinderen@ucc.ie.|Alimentary Pharmabiotic Centre, University College Cork, T12 YT20 Cork, Ireland. d.vansinderen@ucc.ie.
authors.forename: Douwe
authors.initials: D
authors.lastname: van Sinderen
mesh_terms: D000818:Animals; D001435:Bacteriophages / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D044822:Biodiversity; D002611:Cheese / Q000821:virology*; D005285:Fermentation; D014644:Genetic Variation; D016680:Genome, Bacterial; D006358:Hot Temperature; D017045:Lactococcus / Q000821:virology*; D050296:Microbial Viability / Q000528:radiation effects; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012802:Sicily; D000067796:Whey / Q000821:virology*
keywords: Lactococcus lactis; bacteriophage; cheese; dairy fermentation; infection