Genetic and biological characterization of nine Streptococcus salivarius subsp thermophilus bacteriophages

Abstract

Summary -Nine bacteriophages of Streptococcus salivarius subsp thermophilus isolated from different fermentation accidents, with different geographic origins, were compared according to their genomic structures and growth characteristics. Their genomes are linear, double-stranded DNA, with complementary cohesive ends. They belong to one group and are c1assed into 2 closely related strains. The phages of the same strain show the same restriction pattern with BamHI, EcoRI, Hindlll and Pvu II. The bacteriophages <1>81.2 and <l>A 1.1 representative of the strain 1 and strain 2 respectively were characterized and compared according to their morphology, growth characteristics, restriction maps and DNA homology. They belong to Bradley's group B. The optimum concentration of 25 mM was determined for phage infections requiring calcium ions. One-step growth studies show that the latent period is 25 min for both <l>A1.1and <l>B1.2;their burst size is 88 and 56 particles per infected cell, respectively. Their genomes are 36.2 ± 0.5 and 35.6 ± 0.5 kbp in length, respectively.The restriction maps of these genomes are constructed. Cross-hybridization experiments showed that the 2 bacteriophages are clossly related. Using Southern blot hybridization, no homology was detected between the DNA of various bacterial strains, te, strains sensitive or resistant to phage infections, and the <l>B1.2DNA, indicating that these bacteria are not Iysogenic for these phages.

Streptococcus thermophilus bacteriophages

“…Data on growth parameters for S. thermophilus phages are scarce (Binetti, 2001;Deveau et al, 2008;Larbi et al, 1990;Tremblay & Moineau, 1999). Remarkably short latent periods (20e40 min) and very large burst sizes (ranging from 300 to 600 pfu per infection centre) were reported by Binetti (2001) for five of these phages.…”

“…Still, as shown by DNA restriction patterns and host range, a great diversity of phages is often observed in cheese making, Quiberoni, Tremblay, Ackermann, Moineau, & Reinheimer, 2006;Quiberoni et al, 2003). In contrast, several authors from Europe and Argentina reported a more homogenous population of phages in yogurt production facilities (Benbadis, Faelen, Slos, Fazel, & Mercenier, 1990;Brüssow et al, 1994Brüssow et al, , 1998Bruttin et al, 1997;Fayard, Haeflinger, & Accolas, 1993;Larbi, Colmin, Rousselle, Decaris, & Simonet, 1990;Neve, Krusch, & Teuber, 1989;Quiberoni et al, 2003;Suárez, Quiberoni, Binetti, & Reinheimer, 2002). The diversity of phage populations in cheese making may be due to the rotation of multiple strains of S. thermophilus in starter cultures, as compared to yogurt starters, which are much less varied (Brüssow & Kutter, 2005;Quiberoni et al, 2006).…”

Classification of Streptococcus thermophilus Phages Originating from Turkey

“…In a study where EcoRV and EcoRI were used, researchers were able to group the phages into two classifications (Prevots et al 1989). In another study, only two groups were created, even though more enzymes were used (BamHI, EcoRI, HindIII and PvuII), but digestion was possible with BamHI (Larbi et al 1990). However, in the present study, BamHI enzymes did not have any recognition sequences in phage DNA (data not shown).…”

“…The BamHI enzyme was found not to have a restriction site in these phage genomes. Similar restriction enzymes were used in different studies, and by adding other parameters, classification was performed (Prevots et al 1989;Benbadis et al 1990;Larbi et al 1990;Brussow et al 1994;Le Marrec et al 1997;Quiberoni et al 2003). In a study where EcoRV and EcoRI were used, researchers were able to group the phages into two classifications (Prevots et al 1989).…”

“…Besides, when we take protein profiles and host systems into consideration, it is seen that although the phages were grouped into eight according to their minor proteins, this difference was not supported with their host spectrums. For this reason, classification was performed according to protein profiles, restriction endonuclease and hybridization analyses (Neve et al 1989;Prevots et al 1989;Benbadis et al 1990;Larbi et al 1990;Brussow et al 1994;Le Marrec et al 1997;Quiberoni et al 2003). Recently, complete genome sequence analysis has been considered to be quite important.…”