Ultrastructure and Host Specificity of Bacteriophages of Streptococcus cremoris, Streptococcus lactis subsp. diacetylactis, and Leuconostoc cremoris from Finnish Fermented Milk “Viili”

摘要: "Viili," a fermented milk product, has firm but viscous consistency. It is produced with traditional mesophilic mixed-strain starters, which have various stabilities in dairy practice. Thirteen morphologically different types of phages were found 90 viili samples studied by electron microscopy. Ten the phage had isometric heads long, noncontractile tails, two elongated and one unique, very long head short tail. Further morphological differences tail size presence or absence collar, baseplate, fiber. To find hosts for industrially significant phages, we examined sensitivities 500 bacterial isolates from starters viili. Seven attacked Streptococcus cremoris strains, three S. lactis subsp. diacetylactis four Leuconostoc strains. Some differed only their host specificity. Hosts not 4 13 phages.