Fermentation of milk by Streptococcus salivarius subspecies salivarius and Streptococcus salivarius subspecies thermophilus and their use to the yoghurt manufacturer

Unlike Streptococcus salivarius subspecies thermophilus, Streptococcus salivarius subspecies salivarius fails to grow symbiotically in milk in the presence of Lacto-bacillus bulgaricus , does not produce large quantities of the flavour volatiles, acetal-dehyde or diacetyl and is unable to stimulate growth of Lact. bulgaricus by producing formate. Although Strep, salivarius subspecies salivarius and thermophilus have similar DNA base composition and belong in the same DNA homology group, the former is unsuitable for milk fermentations such as yoghurt because fermentation of milk using this organism results in products with poor flavour, aroma and texture.