Thermal inactivation of the heat-resistant Lactococcus lactis bacteriophage P680 in modern cheese processing

Atamer, Zeynep; Hinrichs, Jörg

doi:10.1016/j.idairyj.2009.09.006

Cited by 33 publications

(23 citation statements)

References 24 publications

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“…The phages represent a broad range of 936 phages isolated across Europe (and one New Zealand phage) during a time period that spanned from the 1980s until 2010 (Table 2). First, phages P113g, P272, P680, and 645 were selected, as they had been used in several phage-host interaction studies conducted over the past decades (9,17,25,26). Second, phage 936 P was selected to serve as the prototype member of the 936 phage species for comparative purposes.…”

Section: Resultsmentioning

confidence: 99%

“…2): group I corresponds to what was previously termed the sk1-like or L. lactis subsp. cremoris-infecting phages (25), group II contains the bIL170-like or L. lactis subsp. lactisinfecting phages (25), and group III represents a small yet distinct group of phages that infect primarily L. lactis subsp.…”

Section: Resultsmentioning

confidence: 99%

“…cremoris-infecting phages (25), group II contains the bIL170-like or L. lactis subsp. lactisinfecting phages (25), and group III represents a small yet distinct group of phages that infect primarily L. lactis subsp. lactis strains but are also capable of infecting strains of L. lactis subsp.…”

Section: Resultsmentioning

confidence: 99%

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Investigation of the Relationship between Lactococcal Host Cell Wall Polysaccharide Genotype and 936 Phage Receptor Binding Protein Phylogeny

Mahony

Kot

Murphy

et al. 2013

Appl Environ Microbiol

103

139

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Comparative genomics of 11 lactococcal 936-type phages combined with host range analysis allowed subgrouping of these phage genomes, particularly with respect to their encoded receptor binding proteins. The so-called pellicle or cell wall polysaccharide of Lactococcus lactis, which has been implicated as a host receptor of (certain) 936-type phages, is specified by a large gene cluster, which, among different lactococcal strains, contains highly conserved regions as well as regions of diversity. The regions of diversity within this cluster on the genomes of lactococcal strains MG1363, SK11, IL1403, KF147, CV56, and UC509.9 were used for the development of a multiplex PCR system to identify the pellicle genotype of lactococcal strains used in this study. The resulting comparative analysis revealed an apparent correlation between the pellicle genotype of a given host strain and the host range of tested 936-type phages. Such a correlation would allow prediction of the intrinsic 936-type phage sensitivity of a particular lactococcal strain and substantiates the notion that the lactococcal pellicle polysaccharide represents the receptor for (certain) 936-type phages while also partially explaining the molecular reasons behind the observed narrow host range of such phages. Lactococcal phages are classified into 10 groups based on morphology and DNA hybridization studies (1). Of these, three species are most frequently isolated from dairy environments, namely, the 936, c2, and P335 species (1). The 936 phages are strictly lytic and frequently cause problems for the dairy fermentation industry (2). For this reason, members of this phage species have attracted significant attention in recent years, and the genomes of several phages of this species are now available (3-8). The genome organization of these phages is well conserved and consists of three clusters: the early-, middle-, and late-expressed regions. Comparative genomic analysis of these phages has revealed that while most of the structural genes are highly conserved, there are particular regions of diversity within other regions of their genomes. Among these are the early-expressed genes, which are assumed to encode the replication functions of the phage, as well as the late-expressed region, particularly within the genes encoding the receptor binding protein (RBP) and the tail tape measure protein (TMP) (3,4,8). It has been suggested that the genomes of the 936-type phages can be subgrouped based on these variable regions, which appear to correspond to the subspecies grouping (i.e., Lactococcus lactis subsp. lactis or L. lactis subsp. cremoris) of the host(s) which they infect (3, 9). However, there are a number of exceptions to this in terms of phages that are capable of infecting both subspecies of L. lactis. Phages 645 and P475, for example, are capable of infecting certain members of both subspecies and possess a RBP which is different from those of the two major subgroups of the 936 phages (9). Recently, the RBP structures of phages p2 and bIL170 (or domai...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Investigation of the Relationship between Lactococcal Host Cell Wall Polysaccharide Genotype and 936 Phage Receptor Binding Protein Phylogeny

Mahony

Kot

Murphy

et al. 2013

Appl Environ Microbiol

103

139

View full text Add to dashboard Cite

show abstract

“…In a recent study on phage dissemination in whey powders, it was shown that 94% of the samples contained lytic phages up to titres of 10 7 pfu g À1 (Wagner, 2012). In previous studies, heat inactivation has been studied in detail, and it was documented that most phages can withstand pasteurization processes of 72e75 C for 15e30 s (Atamer et al, 2009;Atamer & Hinrichs, 2010;Müller-Merbach, Neve, & Hinrichs, 2005;Quiberoni, Guglielmotti, & Reinheimer, 2003;Su arez & Reinheimer, 2002). Consequently, thermo-resistant phages are capable of propagating during cheese processing, resulting in phage titres up to 10 9 phages per mL in drained cheese whey (Neve, 1996;Neve, Berger, & Heller, 1995).…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, thermo-resistant phages are capable of propagating during cheese processing, resulting in phage titres up to 10 9 phages per mL in drained cheese whey (Neve, 1996;Neve, Berger, & Heller, 1995). According to Atamer and Hinrichs (2010), a reliable thermal inactivation of heat resistant phages in whey and whey cream is possible, but such harsh heat treatments also cause a significant (approx. 60%) denaturation of whey proteins (Kessler, 2002) and hence, either a loss of or a change in functionality.…”

Section: Introductionmentioning

confidence: 99%