Streptococcus thermophilus

Streptococcus thermophilus is the thermophilic half of the classical yoghurt pair, working alongside Lactobacillus delbrueckii subsp. bulgaricus, and it has been in industrial dairy use since the early twentieth century. It is a Gram-positive, non-motile, non-sporing, catalase-negative facultative anaerobe of the family Streptococcaceae, homofermentative and producing the L(+) isomer of lactic acid, with an optimum growth temperature around 37-45 C. Its genome is compact at roughly 1.8 megabases, a genuinely useful diagnostic detail because that reduction reflects long specialisation to the milk environment: the organism has kept what it needs to grow on lactose and casein and shed much of the rest. It expresses beta-galactosidase, which hydrolyses lactose to glucose and galactose, and many strains produce exopolysaccharides that build texture and body in fermented dairy. Taxonomically it was briefly reduced to a subspecies of Streptococcus salivarius in the 1980s before being restored to full species rank, so both names appear in older literature; Streptococcus thermophilus is the name now in use and the one Thovek declares. Commercially the culture is bought two ways and Thovek supplies both. As a technological starter it is dosed into fermented milk, drinking yoghurt, cultured cream and cheese, where its acidification rate, phage robustness and EPS profile are the selection criteria. As a probiotic ingredient it goes into capsules and multi-strain blends, where the criteria are strain identity, viable count and stability. Freeze-dried concentrate is offered at 100 to 300 billion CFU per gram, with finished capsules built to label strengths from 1 to 50 billion CFU per capsule and a manufacturing overage sized so the printed count still holds at the end of the stated shelf life. The strain designation is declared rather than the species alone, as FSSAI and most export markets require. The organism sits on FSSAI Schedule VII, holds EFSA QPS status - reconfirmed unchanged in the 2025 QPS update - and is long established as safe in US food use. The allergen question here is the commercially important one, and it goes the other way from most of this catalogue. Streptococcus thermophilus is a dairy specialist: it grows rapidly on reconstituted non-fat dried milk, milk-based propagation media are the industry default, and skim milk is a standard freeze-drying cryoprotectant. Unless a dairy-free medium and a non-dairy cryoprotectant are specified at order stage, the finished culture must be declared as containing milk under EU Regulation 1169/2011 Annex II and US FALCPA, and it is vegetarian but not vegan. Dairy-free builds are available and are the right choice for vegan-positioned lines; they carry a separate allergen declaration and a separate CoA. Soy peptone is the second medium component to fix in writing. The capsule shell decides the remaining claim - HPMC for vegan and vegetarian, gelatin for bovine or porcine. No fish, crustacean, molluscan, egg, nut or gluten-containing material enters the process at any stage.